CHAPTER I

Transcriber’s Notes

Obvious typographical errors have been silently corrected. Variations

in hyphenation have been standardised but all other spelling,

punctuation and accents remains unchanged.

Italics are represented thus _italic_, bold thus =bold=.

A reference to Monism as “destructive of culture, etc.” in the index

to page 450, which does not exist, has been changed to 350.

The repetition of section titles on consecutive pages has been removed.

THE CASE AGAINST EVOLUTION

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THE MACMILLAN COMPANY

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TORONTO

THE CASE AGAINST

EVOLUTION

BY

GEORGE BARRY O’TOOLE, PH. D., S.T.D.

PROFESSOR OF THEOLOGY AND PROFESSOR EMERITUS OF PHILOSOPHY,

ST. VINCENT ARCHABBEY; PROFESSOR OF ANIMAL

BIOLOGY, SETON HILL COLLEGE

New York

THE MACMILLAN COMPANY

1926

_All rights reserved_

COPYRIGHT, 1925,

BY THE MACMILLAN COMPANY.

Set up and electrotyped.

Published April, 1925.

Reprinted February, 1926.

_Printed in the United States of America by_

J. J. LITTLE AND IVES COMPANY, NEW YORK

TO MY MOTHER

ADDENDA

NOTE TO PAGE 23.—

As a result of recent investigations on the sex chromosomes and

chromosome numbers in mammals, Theophilus S. Painter reaches the

conclusions that polyploidy cannot be invoked to explain evolution

within this class. After giving a table of chromosome numbers for 7 out

of the 9 eutherian orders, Painter concludes: “The facts recorded above

are of especial interest in that they indicate a unity of chromosome

composition above the marsupial level and effectively dispose of the

suggestion that extensive polyploidy may have occurred within this

subclass.

“In the marsupials the chromosome number is a low one and in the

opossum is 22. At first sight it might appear that the eutherian

condition might have arisen from this by tetraploidy. There are two

objections, however. In the first place the bulk of the chromatin

in marsupials is about the same as in the eutheria, using the sex

chromosome as our measure. In the second place, polyploidy could

scarcely occur successfully in animals with X-Y sex chromosomes, as

most mammals possess, because of the complication occurring in the

sex chromosome balance” (_Science_, April 17, 1925, p. 424). As the

X-Y type of sex chromosomes occurs widely not only among vertebrates,

but also among insects, nematodes, and echinoderms, Painter’s latter

objection excludes evolution by polyploidy from a large portion of the

animal kingdom.

NOTE TO PAGE 90.—

Especially reprehensible, in this respect, are the reconstructions of

the Pithecanthropus, the Eoanthropus, and other alleged pitheco-human

links modeled by McGregor and others. These imaginative productions,

in which cranial fragments are arbitrarily completed and fancifully

overlayed with a veneering of human features, have no scientific

value or justification. It is consoling, therefore, to note that

the great French palæontologist, Marcelin Boule, in his recent book

“Les Hommes Fossiles” (Paris, 1921), has entered a timely protest

against the appearance of such reconstructions in serious scientific

works. “Dubois and Manouvrier,” he says, “have given reconstructions

of the skull and even of the head (of the Pithecanthropus). These

attempts made by medical men, are much too hypothetical, because we

do not possess a single element for the reconstruction of the basis

of the brain case, or of the jawbones. We are surprised to see that a

great palæontologist, Osborn, publishes efforts of this kind. Dubois

proceeded still farther in the realm of imagination when he exhibited

at the universal exposition of Paris a plastic and painted reproduction

of the Pithecanthropus” (_op. cit._, p. 105). And elsewhere he remarks:

“Some true savants have published portraits, covered with flesh and

hair, not only of the Neandertal Man, whose skeleton is known well

enough today, but also of the Man of Piltdown, whose remnants are so

fragmentary; of the Man of Heidelberg, of whom we have only the lower

jawbone; of the Pithecanthropus, of whom there exists only a piece of

the cranium and ... two teeth. Such reproductions may have their place

in works of the lowest popularization. But they very much deface the

books, though otherwise valuable, into which they are introduced.”

... “Men of science—and of conscience—know the difficulties of such

attempts too well to regard them as anything more than a pastime” (_op.

cit._, p. 227).

NOTE TO PAGE 342.—

A fourth possibility is suggested by the case of the so-called skull

of the Galley Hill Man, of whose importance as a prehistoric link Sir

Arthur Keith held a very high opinion, but which has since turned out

to be no skull at all, but merely an odd-shaped piece of stone.

CONTENTS

PAGE

FOREWORD xi

PART I—EVOLUTION IN GENERAL

CHAPTER

I THE PRESENT CRISIS IN EVOLUTIONARY THOUGHT 1

II HOMOLOGY AND ITS EVOLUTIONARY INTERPRETATION 31

III FOSSIL PEDIGREES 66

PART II—THE PROBLEM OF ORIGINS

I THE ORIGIN OF LIFE 131

II THE ORIGIN OF THE HUMAN SOUL 189

III THE ORIGIN OF THE HUMAN BODY 268

AFTERWORD 349

GLOSSARY

INDEX TO AUTHORS

INDEX OF SUBJECTS

FOREWORD

The literature on the subject of evolution has already attained such

vast dimensions that any attempt to add to it has the appearance of

being both superfluous and presumptuous. It is, however, in the fact

that the generality of modern works are frankly partisan in their

treatment of this theme that the publication of the present work finds

justification.

For the philosophers and scientists of the day evolution is evidently

something which admits of no debate and which must be maintained at

all costs. These thinkers are too intent upon making out a plausible

case for the theory to take anything more than the mildest interest in

the facts opposed to it. If they advert to them at all, it is always

to minimize, and never to accentuate, their antagonistic force. For

the moment, at any rate, the minds of scientific writers are closed to

unfavorable, and open only to favorable, evidence, so that one must

look elsewhere than in their pages for adequate presentation of the

case against evolution.

The present work aims at setting forth the side of the question

which it is now the fashion to suppress. It refuses to be bound by

the convention which prescribes that evolution shall be leniently

criticized. It proceeds, in fact, upon the opposite assumption, namely,

that a genuinely scientific theory ought not to stand in need of

indulgence, but should be able, on the contrary, to endure the acid

test of merciless criticism.

Evolution has been termed a “necessary hypothesis.” We have no quarrel

with the phrase, provided it really means evolution as an hypothesis,

and not evolution as a dogma. For, obviously, the problem of a gradual

differentiation of organic species cannot even be investigated upon

the fixistic assumption, inasmuch as this assumption destroys the

problem at the very outset. Unless we assume the possibility, at least,

that modern species of plants and animals may have been the product of

a gradual process, there is no problem to investigate. It is, however,

a far cry from the possibility to the actuality; and the mere fact that

an hypothesis is necessary as an incentive to investigation does not

by any means imply that the result of the investigation will be the

vindication of its inspirational hypothesis. On the contrary, research

often results in the overthrow of the very hypothesis which led to its

inception. We can, therefore, quite readily admit the necessity of

evolution as an hypothesis, while rejecting its necessity as a dogma.

Assent to evolution as a dogma is advocated not only by materialists,

who see in evolutionary cosmogony proof positive of their monism and

the complete overthrow of the idea of Creation, but also by certain

Catholic scientists, who seem to fear that religion may become involved

in the anticipated ruin of fixism. Thus all resistance to the theory

of evolution is deprecated by Father Wasmann and Canon Dorlodot on the

assumption that the ultimate triumph of this theory is inevitable,

and that failure to make provision for this eventuality will lead to

just such another blunder as theologians of the sixteenth century

made in connection with the Copernican theory. Recollection of the

Galileo incident is, doubtless, salutary, in so far as it suggests

the wisdom of caution and the imperative necessity of close contact

with ascertained facts, but a consideration of this sort is no warrant

whatever for an uncritical acceptance of what still remains unverified.

History testifies that verification followed close upon the heels of

the initial proposal of the heliocentric theory, but the whole trend

of scientific discovery has been to destroy, rather than to confirm,

all definite formulations of the evolutional theory, in spite of the

immense erudition expended in revising them.

There is, in brief, no parity at all between Transformism and the

Copernican theory. Among other points of difference, Tuccimei notes

especially the following: “The Copernican system,” he remarks,

“explains _that which is_, whereas evolution attempts to explain _that

which was_; it enters, in other words, into the problem of origins, an

insoluble problem in the estimation of many illustrious evolutionists,

according to whom no experimental verification is possible, given

the processes and factors in conjunction with which the theory was

proposed. But what is of still greater significance for those who

desire to see a parallelism between the two theories is the fact

that the Copernican system became, with the discoveries of Newton, a

demonstrated thesis, scarcely fifty years after the death of Galileo;

the theory of evolution, on the other hand, is at the present day no

longer able to hold its own even as an hypothesis, so numerous are its

incoherencies and the objections to it raised by its own partisans.”

(“La Decadenza di una Teoria,” 1908, p. 11.)

The prospect, then, of a renewal of the Galileo episode is exceedingly

remote. Far more imminent to the writer seems the danger that the

well-intentioned rescuers of religion may be obliged to perform a

most humiliating _volte face_, after having accepted all too hastily

a doctrine favored only for the time being in scientific circles. It

is, in fact, by no means inconceivable that the scientific world will

eventually discard the now prevalent dogma of evolution. In that case

those who have seen fit to reconcile religion with evolution will have

the questionable pleasure of unreconciling it in response to this

reversal of scientific opinion.

On the whole, the safest attitude toward evolution is the agnostic

one. It commits us to no uncertain position. It does not compromise

our intellectual sincerity by requiring us to accept the dogmatism

of scientific orthodoxy as a substitute for objective evidence. It

precludes the possible embarrassment of having to unsay what we

formerly said. And last, but not least, it is the attitude of simple

truth; for the truest thing that Science is, or ever will be, able to

say concerning the problem of organic origins is that she knows nothing

about it.

In the present work, we shall endeavor to show that Evolution has long

since degenerated into a dogma, which is believed in spite of the

facts, and not on account of them. The first three chapters deal with

the theory in general, discussing in turn its genetical, morphological,

and geological aspects. The last three chapters are devoted to the

problem of origins, and treat of the genesis of life, of the human

soul, and of the human body, respectively.

While this book is in no sense a work of “popular science,” I have

sought to broaden its scope and interest by combining the scientific

with the philosophic viewpoint. Certain portions of the text are

unavoidably technical, but there is much, besides, that the general

reader will be able to follow without difficulty. Students, especially

of biology, geology, and experimental psychology, may use it to

advantage as supplementary reading in connection with their textbooks.

I wish to acknowledge herewith my indebtedness to the Editor of the

_Catholic Educational Review_, Rev. George Johnson, Ph. D., to whose

suggestion and encouragement the inception of this work was largely

due. I desire also to express my sincere appreciation of the services

rendered in the revision of the manuscript by the Rev. Edward Wenstrup,

O.S.B., Professor of Zoölogy, St. Vincent College, Pennsylvania.

BARRY O’TOOLE.

ST. VINCENT ARCHABBEY,

January 30, 1925.

PART I

EVOLUTION IN GENERAL

CHAPTER I

THE PRESENT CRISIS IN EVOLUTIONARY THOUGHT

Three prominent men, a scientist, a publicist, and an orator, have

recently made pronouncements on the theory of Evolution. The trio, of

course, to whom allusion is made, are Bateson, Wells, and Bryan. As

a result of their utterances, there has been a general reawakening

of interest in the problem to which they drew attention. Again and

again, in popular as well as scientific publications, men are raising

and answering the question: “Is Darwinism dead?” Manifold and various

are the answers given, but none of them appears to take the form

of an unqualified affirmation or negation. Some reply by drawing a

distinction between Darwinism, as a synonym for the theory of evolution

in general, and Darwinism, in the sense of the particular form of that

theory which had Darwin for its author. Modern research, they assure

us, has not affected the former, but has necessitated a revision of

ideas with respect to the latter. There are other forms of evolution

besides Darwinism, and, as a matter of fact, not Darwin, but Lamarck

was the originator of the scientific theory of evolution. Others,

though imitating the prudence of the first group in their avoidance of

a categorical answer, prefer to reply by means of a distinction based

upon their interpretation of the realities of the problem rather than

upon any mere terminological consideration.

Of the second group, some, like Osborn, distinguish between the _law_

of evolution and the theoretical _explanations_ of this law proposed by

individual scientists. The existence of the law itself, they insist, is

not open to question; it is only with respect to hypotheses explanatory

of the aforesaid law that doubt and disagreement exist. The obvious

objection to such a solution is that, if evolution is really a law of

nature, it ought to be reducible to some clear-cut mathematical formula

comparable to the formulations of the laws of constant, multiple, and

reciprocal proportion in chemistry, or of the laws of segregation,

assortment, and linkage in genetics. Assuming, then, that it is a

genuine law, how is it that today no one ventures to formulate this

evolutional law in definite and quantitative terms?

Others, comprising, perhaps, a majority, prefer to distinguish between

the _fact_ and the _causes_ of evolution. Practically all scientists,

they aver, agree in accepting evolution as an established fact; it is

only with reference to the agencies of evolution that controversy and

uncertainty are permissible. To this contention one may justly reply

that, by all the canons of linguistic usage, a fact is an observed or

experienced event, and that hitherto no one in the past or present

has ever been privileged to witness with his senses even so elemental

a phenomenon in the evolutionary process as the actual origin of a

new and genuine organic species. If, however, the admission be made

that the term “fact” is here used in an untechnical sense to denote

an inferred event postulated for the purpose of interpreting certain

natural phenomena, then the statement that the majority of modern

scientists agree as to the “fact” of evolution may be allowed to stand,

with no further comment than to note that the formidable number and

prestige of the advocates fail to intimidate us. Considerations of this

sort are wholly irrelevant, for in science no less than in philosophy

authority is worth as much as its arguments and no more.

The limited knowledge of the facts possessed by the biologists of

the nineteenth century left their imaginations perilously unfettered

and permitted them to indulge in a veritable orgy of theorizing. Now,

however, that the trail blazed by the great Augustinian Abbot, Mendel,

has been rediscovered, work of real value is being done with the seed

pan, the incubator, the microtome, etc., and the wings of irresponsible

speculation are clipped. Recent advances in this new field of Mendelian

genetics have made it possible to subject to critical examination

all that formerly went under the name of “experimental evidence” of

evolution. Even with respect to the inferential or circumstantial

evidence from palæontology, the enormous deluge of fossils unearthed

by the tireless zeal of modern investigators has annihilated, by its

sheer complexity, the hasty generalizations and facile simplifications

of a generation ago, forcing the adoption of a more critical

attitude. Formerly, a graded series of fossil genera sufficed for

the construction of a “palæontological pedigree”; now, the worker in

this field demands that the chain of descent shall be constructed

with species, instead of genera, for links—“Not till we have linked

species into lineages, can we group them into genera.” (F. A. Bather,

_Science_, Sept. 17, 1920, p. 264.) This remarkable progress in

scientific studies has tended to precipitate the crisis in evolutionary

thought, which we propose to consider in the present chapter. Before

doing so, however, it will be of advantage to formulate a clear

statement of the problem at issue.

Evolution, or transformism, as it is more properly called, may be

defined as the theory which regards the present species of plants and

animals as modified descendants of earlier forms of life. Nowadays,

therefore, the principal use of the term evolution is to denote the

developmental theory of organic species. It is, however, a word of many

senses. In the eighteenth century, for example, it was employed in a

sense at variance with the present usage, that is, to designate the

non-developmental theory of embryological encasement or preformation

as opposed to the developmental theory of epigenesis. According

to the theory of encasement, the adult organism did not arise by

the generation of new parts (epigenesis), but by a mere “unfolding”

(_evolutio_) of preëxistent parts. At present, however, evolution is

used as a synonym for transformism, though it has other meanings,

besides, being sometimes used to signify the formation of inorganic

nature as well as the transformation of organic species.

Evolution, in the sense of transformism, is opposed to fixism, the

older theory of Linné, according to whom no _specific_ change is

possible in plants and animals, all organisms being assumed to have

persisted in essential sameness of type from the dawn of organic life

down to the present day. The latter theory admits the possibility of

environmentally-induced modifications, which are non-germinal and

therefore non-inheritable. It also admits the possibility of germinal

changes of the varietal, as opposed to the specific, order, but it

maintains that all such changes are confined within the limits of the

species, and that the boundaries of an organic species are impassable.

Transformism, on the contrary, affirms the possibility of specific

change, and assumes that the boundaries of organic species have

actually been traversed.

What, then, is an organic species? It may be defined as a group of

organisms endowed with the _hardihood_ necessary to survive and

propagate themselves under natural conditions (_i.e._ in the wild

state), exhibiting a common inheritable type, differing from one

another by no major germinal difference, perfectly interfertile with

one another, but _sexually incompatible_ with members of an alien

specific group, in such wise that they produce hybrids wholly, or

partially, sterile, when crossed with organisms outside their own

specific group.

David Starr Jordan has wisely called attention to the requisite of

viability and survival under natural conditions. “A species,” he says,

“is not merely a form or group of individuals distinguished from other

groups by definable features. A complete definition involves longevity.

A species is a kind of animal or plant which has run the gauntlet

of the ages and persisted.... A form is not a species until it has

‘stood.’” (_Science_, Oct. 20, 1922, p. 448.)

Sexual (gametic) incompatibility as a criterion of specific

distinction, presupposes the bisexual or biparental mode of

reproduction, namely, syngamy, and is therefore chiefly applicable

to the metista, although, if the view tentatively proposed by the

protozoölogist, E. A. Minchin, be correct, it would also be applicable

to the protista. According to this view, no protist type is a

true species, unless it is maintained by syngamy (_i.e._ bisexual

reproduction)—“Not until syngamy was acquired,” says Minchin, “could

true species exist among the Protista.” (“An Introduction to the Study

of the Protozoa,” p. 141.)

To return, however, to the metista, the horse (_Equus caballus_) and

the ass (_Equus asinus_) represent two distinct species under a common

genus. This is indicated by the fact that the mule, which is the hybrid

offspring of their cross, is entirely sterile, producing no offspring

whatever, when mated with ass, horse, or mule. Such total sterility,

however, is not essential to the proof of specific differentiation; it

suffices that the hybrid be less fertile than its parents. As early as

1686, sterility (total or partial) of the hybrid was laid down by John

Ray as the fundamental criterion of specific distinction. Hence Bateson

complains that Darwinian philosophy flagrantly “ignored the chief

attribute of species first pointed out by John Ray that the product of

their crosses is frequently sterile in a greater or lesser degree.”

(_Science_, Jan. 20, 1922, p. 58.)

Accordingly, the sameness of type required in members of the same

species refers rather to the genotype, that is, the sum-total of

internal hereditary factors latent in the germ, than to the phenotype,

that is, the expressed somatic characters, viz. the color, structure,

size, weight, and all other perceptible properties, in terms of which a

given plant or animal is described. Thus it sometimes happens that two

distinct species, like the pear-tree and the apple-tree, resemble each

other more closely, as regards their external or somatic characters,

than two varieties belonging to one and the same species. Nevertheless,

the pear-tree and the apple-tree are so unlike in their germinal

(genetic) composition that they cannot even be crossed.

According to all theories of transformism, new species arise through

the transformation of old species, and hence evolutionists are at

one in affirming the occurrence of specific change. When it comes,

however, to assigning the agencies or factors, which are supposed to

have brought about this transmutation of organic species, there is a

wide divergence of opinion. The older systems of transformism, namely,

Lamarckism and Darwinism, ascribed the modification of organic species

to the operation of the external factors of the environment, while the

later school of orthogenesis attributed it to the exclusive operation

of factors residing within the organism itself.

Lamarckism, for example, made the formation of organs a response to

external conditions imposed by the environment. The elephant, according

to this view, being maladjusted to its environment by reason of its

clumsy bulk, developed a trunk by using its nose to compensate for

its lack of pliancy and agility. Here the use or function precedes

the organ and molds the latter to its need. Darwinism agrees with

Lamarckism in making the environment the chief arbiter of modification.

Its explanation of the elephant’s trunk, however, is negative rather

than positive. This animal, it tells us, developed a trunk, because

failure to vary in that useful direction would have been penalized by

extermination.

Wilson presents, in a very graphic manner, the appalling problem

which confronts evolutionists who seek to explain the adaptations of

organisms by means of environmental factors. Referring, apparently, to

Henderson’s “Fitness of the Environment,” he says: “It has been urged

in a recent valuable work ... that fitness is a reciprocal relation,

involving the environment no less than the organism. This is both

a true and suggestive thought; but does it not leave the naturalist

floundering amid the same old quicksands? The historical problem

with which he has to deal must be grappled at closer quarters. He is

everywhere confronted with specific devices in the organism that must

have arisen long after the conditions of environment to which they

are adjusted. Animals that live in water are provided with gills.

Were this all, we could probably muddle along with the notion that

gills are no more than lucky accidents. But we encounter a sticking

point in the fact that gills are so often accompanied by a variety of

ingenious devices, such as reservoirs, tubes, valves, pumps, strainers,

scrubbing brushes, and the like, that are obviously tributary to the

main function of breathing. Given water, asks the naturalist, how has

all this come into existence and been perfected? The question is an

inevitable product of our common sense.” (Smithson. Inst. Rpt. for

1915, p. 405.)

Impressed with the difficulty of accounting for the phenomena of

organic adaptation by means of the far too general and unspecific

influence of the environment, the orthogenetic school of transformism

inaugurated by Nägeli, Eimer, and Kölliker repudiated this explanation,

and sought to explain organic evolution on the sole basis of internal

factors, such as “directive principles,” or germinal determinants.

According to this conception, the elephant first developed his trunk

under the drive of some internal agency, and afterwards sought out an

environment in which the newly-developed trunk would be useful. In

other words, orthogenesis makes the organ precede the function, and is

therefore the exact reverse of Lamarckism.

Evolutionists in general, as we have said, regard our present plants

and animals as the modified progeny of earlier forms, understanding

by “modified” that which is the product of a trans-specific,

as distinguished from a varietal or intra-specific, change. To

substantiate the claim that changes of specific magnitude have actually

taken place, they appeal to two principal kinds of evidence, namely:

(a) empirical evidence based on such variations as are now observed

to occur among living organisms; (b) inferential evidence, which

aposterioristically deduces the common ancestry of allied organic

types from their resemblances and their sequence in geological time.

Hence, if we omit as negligible certain subsidiary arguments, the

whole evidence for organic evolution may be summed up under three

heads: (1) the genetic evidence grounded on the facts of variation;

(2) the zoölogical evidence based on homology, that is, on structural

resemblance together with all further resemblances (physiological and

embryological), which such similarity entails; (3) the palæontological

evidence which rests on the gradual approximation of fossil types to

modern types, when the former are ranged in a series corresponding to

the alleged chronological order of their occurrence in the geological

strata. It is the bearing of recent genetical research upon the first

of these three lines of evidence that we propose to examine in the

present chapter, an objective to which a brief and rather eclectic

historical survey of evolutionary thought appears to offer the easiest

avenue of approach.

While many bizarre speculations on the subject of transformism had

been hazarded in centuries prior to the nineteenth, the history

of this conception, as a scientific hypothesis, dates from the

publication of Lamarck’s “Philosophie Zoologique” in 1809. According

to Lamarck, organic species are changed as a result of the _indirect_

influence of the external conditions of life. A change in environment

forces a change of habit on the part of the animal. A change in the

animal’s habits results in adaptation, that is, in the development or

suppression of organs through use or disuse. The adaptation, therefore,

thus acquired was not directly imposed by the environment, but only

indirectly—that is, through the mediation of habit. Once acquired

by the individual animal, however, the adaptation was, so Lamarck

thought, taken up by the process of inheritance and perpetuated by

being transmitted to the animal’s offspring. The net result would be a

progressive differentiation of species due to this indirect influence

of a varying environment.

Such was the theory of Lamarck, and it is sound and plausible in all

respects save one, namely, the unwarranted assumption that acquired

adaptations are inheritable, since these, to quote the words of the

Harvard zoölogist, G. H. Parker, “are as a matter of fact just the

class of changes in favor of the inheritance of which there is the

least evidence.” (“Biology and Social Problems,” 1914, p. 103.)

The next contribution to the philosophy of transformism was made by

Charles Darwin, when, in the year 1859, he published his celebrated

“Origin of Species.” In this work, the English naturalist bases the

evolution of organic species upon the assumed spontaneous tendency

of organisms to vary minutely from their normal type in every

possible direction. This spontaneous variability gives rise to slight

variations, some of which are advantageous, others disadvantageous to

the organism. The enormous fecundity of organisms multiplies them in

excess of the available food supply, and more, accordingly, are born

than can possibly survive. In the ensuing competition or struggle for

existence, individuals favorably modified survive and propagate their

kind, those unfavorably modified perish without progeny. This process

of elimination Darwin termed natural selection. Only individuals

favored by it were privileged to propagate their kind, and thus it

happened that these minute variations of a useful character were seized

upon and perpetuated “by the strong principle of _inheritance_.” In

this way, these slight but useful modifications would tend gradually

to accumulate from generation to generation in the direction favored

by “natural selection,” until, by the ensuing summation of innumerable

minor differences verging in the same direction, a major difference

would be produced. The end-result would be a progressive _divergence_

of posterity from the common ancestral type, whence they originally

sprang, ending in a multiplicity of new forms or species, all differing

to a greater or lesser extent from the primitive type. The contrary

hypothesis of a possible _convergence_ of two originally diverse types

towards eventual similarity Darwin rejected as an extremely improbable

explanation of the observed resemblance of organic forms, which, not

without reason, he thought it more credible to ascribe to their assumed

divergence from a common ancestral type.

Such was the scheme of evolution elaborated by Charles Darwin. His

hypothesis leaves the origin of variations an unsolved mystery. It

assumes what has never been proved, namely, the efficacy of “natural

selection.” It rests on what has been definitely disproved by factual

evidence, namely, the inheritability of the slight variations, now

called fluctuations, which, not being transmitted even, by the

hereditary process, cannot possibly accumulate from generation to

generation, as Darwin imagined. Moreover, fluctuations owe their

origin to variability in the external conditions of life (_e.g._ in

temperature, moisture, altitude, exposure, soil, food, etc.), being

due to the _direct_ influence or pressure of the environment, and not

to any spontaneous tendency within the organism itself. Hence Darwin

erred no less with respect to the spontaneity, than with respect to the

inheritability and summation, of his “slight variations.”

The subsequent history of Lamarckian and Darwinian Transformism is

briefly told. That both should pass into the discard was inevitable,

but, thanks to repeated revisions undertaken by loyal adherents, their

demise was somewhat retarded. In vain, however, did the Neo-Darwinians

attempt to do for Darwinism what the Neo-Lamarckians had as futilely

striven to do for Lamarckism. The revisers succeeded only in

precipitating a lethal duel between these two rival systems, which

has proved disastrous to both. The controversy begun in 1891 between

Herbert Spencer and August Weismann marked the climax of this fatal

conflict.

Spencer refused to see any value whatever in Darwin’s principle of

natural selection, while other Neo-Lamarckians, less extreme, were

content to relegate it to the status of a subordinate factor in

evolution. Darwin had considered it “the most important means of

modification,” but it is safe to say that no modern biologist attaches

very much importance to natural selection as a means of accounting for

the differences which mark off one species from another. In fact, if

natural selection has enjoyed, or still continues to enjoy, any vogue

at all, it is not due to its value in natural science (which, for all

practical intents and purposes, is nil), but solely to its appeal as

“mechanistic solution”; for nothing further is needed to commend it to

modern thinkers infected with what Wasmann calls _Theophobia_. Natural

selection, in making the organism a product of the concurrence of blind

forces unguided by Divine intelligence, a mere fortuitous result, and

not the realization of purpose, has furnished the agnostic with a

miserable pretext for omitting God from his attempted explanation of

the universe. “Here is the knot,” exclaims Du Bois-Reymond, “here the

great difficulty that tortures the intellect which would understand the

world. Whoever does not place all activity wholesale under the sway of

Epicurean chance, whoever gives only his little finger to teleology,

will inevitably arrive at Paley’s discarded ‘Natural Theology,’ and

so much the more necessarily, the more clearly he thinks and the

more independent his judgment.... The possibility, ever so distant,

of banishing from nature its seeming purpose, and putting a blind

necessity everywhere in the place of final causes, appears, therefore,

as one of the greatest advances in the world of thought, from which

a new era will be dated in the treatment of these problems. To have

somewhat eased the torture of the intellect which ponders over the

world-problem will, as long as philosophical naturalists exist, be

Charles Darwin’s greatest title to glory.” (_Darwin versus Galiani_,

“Reden,” Vol. I, p. 211.)

But however indispensable the selection principle may be to a

philosophy which proposes to banish the Creator from creation, its

scientific insolvency has become so painfully apparent that biologists

have lost all confidence in its power to solve the problem of organic

origins. It is recognized, for example, that natural selection would

suppress, rather than promote, development, seeing that organs

have utility only in the state of perfection and are destitute of

selection-value while in the imperfect state of transition. Again, the

specific differences that diversify the various types of plants and

animals are notoriously deficient in selection-value, and therefore the

present differentiation of species cannot be accounted for by means of

the principle of natural selection. Finally, unless one is prepared

to make the preposterous assumption that the environment is a telic

mechanism expressly designed for shaping organisms, he is under logical

necessity of admitting that the influence of natural selection cannot

be anything else than purely destructive. There is, as Wilson points

out, no aprioristic ground for supposing that natural selection could

do anything more than maintain the _status quo_, and as for factual

proofs of its effectiveness in a positive sense, they are wholly

wanting. Professor Caullery of the Sorbonne, in his Harvard lecture

of Feb. 24, 1916, assures us that, “since the time of Darwin, natural

selection has remained a purely speculative idea and that no one has

been able to show its efficacy in concrete indisputable examples.”

Considerations of this sort induced not only Neo-Lamarckians, but

many non-partisans as well, to take the field against the Darwinian

Selection Principle. Thus Spencer’s caustic attack became a forerunner

of others, and eminent biologists, like Fleischmann, Driesch, T. H.

Morgan, and Bateson, have in turn poured the vials of their satire

upon the attempts of Neo-Darwinians to rehabilitate the philosophy

of natural selection. Wm. Bateson warns those, who persist in their

credulity with reference to the Darwinian account of organic teleology,

that they “will be wise henceforth to base this faith frankly on the

impregnable rock of superstition and to abstain from direct appeals

to natural fact.” This admonition forms the conclusion of a scathing

criticism of what he styles the “fustian of Victorian philosophy.”

“In the face of what we know,” it runs, “of the distribution of

variability in nature, the scope claimed for natural selection must

be greatly reduced. The doctrine of the survival of the fittest is

undeniable so long as it is applied to the organism as a whole, but to

attempt by this principle to find value in all definiteness of parts

and functions, and in the name of science to see fitness everywhere,

is mere eighteenth century optimism. Yet it was in its application to

the parts, to the details of specific difference, to the spots on the

peacock’s tail, to the coloring of an orchid flower, and hosts of such

examples, that the potency of natural selection was urged with greatest

emphasis. Shorn of these pretensions the doctrine of the survival of

favored races is a truism, helping scarcely at all to account for the

diversity of species. Tolerance plays almost as considerable a part.

By these admissions the last shred of that teleological fustian with

which Victorian philosophy loved to clothe the theory of evolution is

destroyed.” (_Heredity_, “Presidential Address to Brit. Ass’n. for

Advanc. of Science,” Aug. 14, 1914.) Nor is this all. The Darwinian

Selection Principle is reproached with having retarded the progress

of science. It is justly accused of having discouraged profound and

painstaking analysis by putting into currency its shallow and spurious

solution of biological problems. “Too often in the past,” says Edmund

Wilson, “the facile formulas of natural selection have been made use of

to carry us lightly over the surface of unsuspected depths that would

have richly repaid serious exploration.” (Smithson. Inst. Rpt. for

1915, p. 406.)

In retaliation for the destructive criticism of natural selection,

the Neo-Darwinians have proceeded to pulverize the Lamarckian tenet

concerning the inheritability of acquired adaptations. Weismann, having

laid down his classic distinction between the _soma_ (comprising the

vegetative or tissue cells in contact with the environment) and the

_germ_ (_i.e._ the sequestered reproductive cells or gametes, which are

sheltered from environmental vicissitudes), showed that the Lamarckian

assumption that a change in the somatic cells (which constitute the

organism of the individual) is registered in the germ cells (which

constitute the vehicle of racial inheritance), is supported neither

by _a priori_ probability nor by any facts of observation. Germ cells

give rise by division to somatic or tissue cells, but the converse is

not true; for, once a cell has become differentiated and specialized

into a tissue cell, it can never again give rise by division to germ

cells, but only to other tissue cells of its own kind. Hence the

possibility of a change in the tissue being transmitted to the germ

has no antecedent probability in its favor. Neither is it grounded on

the facts of observation. Bodily mutilations of the parent are not

transmitted to the offspring. The child of a blacksmith is not born

with a more developed right arm than that of a tailor’s child. When

the ovaries from a white rabbit are grafted into a black rabbit, whose

own ovaries have been previously removed, the latter, if mated to a

white male, will produce spotlessly white young. Hence the offspring

inherit the characters of the germ track of the white female, whence

the ovaries were derived, without being influenced in the least by the

pigmented somatic cells of the nurse-body (_i.e._ the black female),

into which the ovaries were grafted. Kammerer’s experiments, in which

young salamanders were found to exhibit at birth the coloration, which

their parents had acquired through the action of sunlight, fail to

convince, because, in this case, the bodies of the parents are not

sufficiently impervious to light to preclude its direct action upon

the gametes while in the reproductive organs of the parents. Hence we

cannot be sure but that the coloration of the offspring derived from

these gametes is due to the direct agency of sunlight rather than to

the intermediate influence of the modified somatic cells upon the germ

plasm.

The same objection holds true of the recent experiments, in which

the germ cells have been modified by modifying the interior medium

or internal environment by means of antibodies and hormones. No

one doubts the possibility of influencing heredity by a direct

modification of the germ cells, especially when, as is always the

case in these experiments, the modification produced is destructive

rather than constructive. The experiments, therefore, of Prof. M.

F. Guyer of Wisconsin University, in which a germinally-transmitted

eye defect was produced by injecting pregnant female rabbits with

an antilens serum derived from fowls immunized to the crystalline

lens of rabbits as antigen, are beside the mark. To demonstrate

the Lamarckian thesis one must furnish evidence of a constructive

addition to inheritance by means of prior somatic acquisition. The

transmission of defects artificially produced is not so much a process

of inheritance (transmission of type) as rather one of degeneracy

(failure to equate the parental type).[1] Commenting on Guyer’s

suggestion that an organism capable of producing antibodies that are

germinally-destructive, may also be able to produce constructive

bodies, Prof. Edwin S. Goodrich says: “The real weakness of the theory

is that it does not escape from the fundamental objections we have

already put forward as fatal to Lamarckism. If an effect has been

produced, either the supposed constructive substance was present from

the first, as an ordinary internal environmental condition necessary

for the normal development of the character, or it must have been

introduced from without by the application of a new stimulus. The same

objection does not apply to the destructive effect. No one doubts that

if a factor could be destroyed by a hot needle or picked out with a

fine forceps the effect of the operation would persist throughout

subsequent generations.” (_Science_, Dec. 2, 1921, p. 535.)

[1] A good definition of degeneracy is that of A. F. Tredgold,

who says: “I venture to define degeneracy as ‘a retrograde

condition of the individual resulting from a pathological

variation of the germ cell.’” (Smithson. Inst. Rpt. for 1918,

p. 548.)

But in demonstrating against the Neo-Lamarckians that somatic

modifications unrepresented in the germ plasm could have no

significance in the process of racial evolution, Weismann had _proved

too much_. His argument was no less telling against Darwinism than

it was against Lamarckism. Darwin’s “individual differences” or

“slight variations,” now spoken of as fluctuations, were quite as

unrepresented and unrecorded in the germ cells as Lamarck’s “acquired

adaptations.” There can be no “summation of individual differences”

for the simple reason that fluctuations have no germinal basis and

are therefore uninheritable—“We must bear in mind the fact,” says

Prof. Edmund Wilson, “that Darwin often failed to distinguish between

non-inheritable fluctuations and hereditary mutations of small degree.”

(Smithson. Inst. Rpt. for 1915, p. 406.) Fluctuations, as we have

seen, are due to variability in the environmental conditions, _e.g._

in access to soil nutrients, etc. As an instance of fluctuational

variation the seeds of the ragweed may be cited. Normally these

seeds have six spines, but around this average there is considerable

fluctuation in individual seeds, some having as many as nine spines

and others no more than one. Yet the plants reared from nine-spine

seeds, even when similarly mated, show no greater tendency to produce

nine-spine seeds than do plants reared from one-spine seeds.

To meet the difficulty presented by the non-inheritability of the

Lamarckian adaptation and the Darwinian fluctuation, De Vries

substituted for them those rare and abruptly-appearing inheritable

variations, which he called mutations[2] and regarded as elementary

steps in the evolutionary process. This new version of transformism

was announced by De Vries in 1901, and more fully explained in his

“Die Mutations-Theorie” (Leipzig, 1902-1903). Renner has shown that De

Vries’ new forms of Œnothera were cases of complex hybridization rather

than real mutants, as the forms produced by mutation are now called.

Nevertheless, the work of Morgan, Bateson, and others leaves little

doubt as to the actual occurrence of _factorial_ mutants, while Dr.

Albert F. Blakeslee has demonstrated the existence of _chromosomal_

mutants. When unqualified, the term mutant usually denotes the

factorial mutant, which arises from a change in one or more of the

concatenated genes (hereditary factors) of a single chromosome (nuclear

thread) in the germinal (_i.e._ gametic) complex. All such changes

are called factorial mutations. They are hereditarily transmissible,

and affect the somatic characters of the race permanently, although,

in rare cases, such as that of the bar-eyed Drosophila mutant, the

phenomenon of _reversion_ has been observed. The chromosomal mutant,

on the contrary, is not due to changes in the single factors or genes,

but to duplication of one or more entire chromosomes (linkage-groups)

in the gametic complex. Like the factorial mutant, it produces a

permanent and heritable modification. The increase in nuclear material

involved in chromosomal mutation (_i.e._ duplication) seems to cause a

proportionate increase in the cytoplasmic mass of the single somatic

cells, which manifests itself in the phenotype as giantism. De

Vries’ _Œnothera gigas_ is a chromosomal mutant illustrative of this

phenomenon. Besides the foregoing, there is the _pseudomutant_ produced

by the factorial recombination, which results from a _crossover_,

_i.e._ an exchange of genes or factors between two germinal chromosomes

of the same synaptic pair. This reciprocal transfer of genes from one

homologous chromosome to another happens, in a certain percentage of

cases, during synapsis. The percentage can be artificially increased by

exposing young female hybrids to special conditions of temperature.

[2] The term mutation had been used long before and in a

similar sense by the German palæontologist Waagen, who employed

it to designate the variations of a specific type that succeed

one another in successive strata, a thing which rarely occurs.

(Cf. Waagen’s _Die Formenreihe des Ammonites subradiatus_,

Geognost. paläont. Beitr., Berlin, 1869.)

If these new mutant forms could be regarded as genuine new species,

then the fact that such variations are heritable and come within the

range of actual observation, would constitute the long-sought empirical

proof of the reality of evolution. Consciously or subconsciously,

however, De Vries recognized that this was not the case; for he refers

to mutants as “elementary species,” and does not venture to present

them as authentic organic species.

The factorial mutant answers neither the endurance test nor the

intersterility test of a genuine species. It would, doubtless, be

going too far to regard all such mutant forms as examples of germinal

degeneracy, but it cannot be denied that all of them, when compared

to the wild type, are in the direction of unfitness, none of them

being viable and prosperous under the severe conditions obtaining in

the wild state. Bateson, who seems to regard all mutant characters as

recessive and due to germinal loss, declares: “Even in Drosophila,

where hundreds of genetically distinct factors have been identified,

very few new dominants, that is to say positive additions, have been

seen, and I am assured that none of them are of a class which could be

expected to be viable under natural conditions. I understand even that

none are certainly viable in the homozygous state.” (Toronto Address,

_Science_, Jan. 20, 1922, p. 59.) “Garden or greenhouse products,”

says D. S. Jordan, “are immensely interesting and instructive, but

they throw little light on the origin of species. To call them species

is like calling dress-parade cadets ‘soldiers.’ I have heard this

definition of a soldier, ‘one that has stood.’ It is easy to trick out

a group of boys to look like soldiers, but you can not define them as

such until they have ‘stood.’” (_Science_, Oct. 20, 1922.) In a word,

factorial mutants, owing, as they do, their survival exclusively to

the protection of artificial conditions, could never become the hardy

pioneers of new species.

Bateson insists that the mutational variation represents a change of

loss. “Almost all that we have seen,” he says, “are variations in

which we recognize that elements have been lost.” (_Science_, Jan.

20, 1922, p. 59.) In his Address to the British Association (1914),

he cites numerous examples tending to show that mutant characters are

but diminutions or intensifications of characters pre-existent in the

wild or normal stock, all of which are explicable as effects of the

loss (total or partial) of either positive, or inhibitive (epistatic)

hereditary factors (genes). One of these instances illustrating the

subtractive nature of the factorial mutation is that of the Primula

“Coral King,” a salmon-colored mutant, which was suddenly given off

by a red variety of Primula called “Crimson King.” Such a mutation

is obviously based on the loss of a germinal factor for color. The

loss, however, is sometimes partial rather than total, as instanced in

the case of the purple-edged Picotee sweet pea, which arose from the

wholly purple wild variety by fractionation of the genetic factor for

purple pigment. Even where the mutational variation appears to be one

of gain, as happens when a positive character appears _de novo_ in the

phenotype, or when a dilute parental character is intensified in the

offspring, it is, nevertheless, interpretable as a result of germinal

loss, the loss, namely, total or partial, of a genetic inhibitor. Such

inhibitive genes or factors are known to exist. Bateson has shown,

for example, that the whiteness of White Leghorn chickens is due, not

to the absence of color-factors, but to the presence of a genetic

inhibitor—“The white of White Leghorns,” he says, “is not, as white

in nature often is, due to the loss of the color elements, but to the

action of something which inhibits their expression.” (Address to the

Brit. Ass’n., Smithson. Inst. Rpt. for 1915, p. 368.) Thus the sudden

appearance in the offspring of a character not visibly represented in

the parents may be due, not to germinal acquisition, but the loss of

an inhibitory gene, whose elimination allows the somatic character

previously suppressed by it to appear. Hence Bateson concludes: “In

spite of seeming perversity, therefore, we have to admit that there is

no evolutionary change which in the present state of our knowledge we

can positively declare to be not due to loss.” (_Loc. cit._, p. 375.)

Another consideration, which disqualifies the factorial mutant for the

rôle of a new species, is its failure to pass the test of interspecific

sterility. When individuals from two distinct species are crossed,

the offspring of the cross is either completely sterile, as instanced

in the mule, or at least partially so. But when, for example, the

sepia-eyed mutant of the vinegar fly is back-crossed with the red-eyed

wild type, whence it originally sprang, the product of the cross is

a red-eyed hybrid, which is perfectly fertile with other sepia-wild

hybrids, with wild flies, and with sepia mutants. This proves that

the sepia-eyed mutant has departed, so to speak, only a varietal,

and not a specific, distance away from the parent stock. Ordinary

or factorial mutation does not, therefore, as De Vries imagined,

produce new species. These mutants do, indeed, meet the requirement of

permanent transmissibility, for their distinctive characters cannot

be obliterated by any amount of crossing. Nevertheless, the factorial

mutation falls short of being an empirical proof of evolution, because

it is a varietal, and not a specific, change. In other words, factorial

mutants are new varieties and not new species. Only a heritable change

based on germinal acquisition of sufficient magnitude to produce

gametic incompatibility between the variant and the parent type would

constitute direct evidence of the transmutation of species, provided,

of course, that the variant were also capable of survival under the

natural conditions of the wild state.

In his Toronto address of December 28, 1921, Wm. Bateson announced

the failure of De Vries’ Mutation Theory, when he said: “But that

particular and essential bit of the theory of evolution, which is

concerned with the origin and nature of species remains utterly

mysterious. We no longer feel as we used to do, that the process of

variation, now contemporaneously occurring, is the beginning of a work

which needs merely the element of time for its completion; for even

time cannot complete that which has not yet begun. The conclusion in

which we were brought up that species are a product of a summation of

variations ignored the chief attribute of species first pointed out by

John Ray that the product of their crosses is frequently sterile in

greater or less degree. Huxley, very early in the debate, pointed out

this grave defect in the evidence, but before breeding researches had

been made on a large scale no one felt the objection to be serious.

Extended work might be trusted to supply the deficiency. It has not

done so, and the significance of the negative evidence can no longer be

denied....

“If species have a common origin where did they pick up the ingredients

which produce this sexual incompatibility? Almost certainly it is a

variation in which something has been added. We have come to see that

variations can very commonly—I do not say always—be distinguished as

positive and negative.... Now we have no difficulty in finding evidence

of variation by loss, but variations by addition are rarities, even

if there are any such which must be so accounted. The variations to

which interspecific sterility is due are obviously variations in which

something is apparently added to the stock of ingredients. It is one of

the common experiences of the breeder that when a hybrid is partially

sterile, and from it any fertile offspring can be obtained, the

sterility, once lost, disappears. This has been the history of many,

perhaps most, of our cultivated plants of hybrid origin.

“The production of an indubitably sterile hybrid from completely

fertile parents which has arisen under critical observation is the

event for which we wait. Until this event is witnessed, our knowledge

of evolution is incomplete in a vital respect. From time to time such

an observation is published, but none has yet survived criticism.”

(_Science_, Jan. 20, 1922, pp. 58, 59.)

But what of the chromosomal mutant? For our knowledge of this type

of mutation we are largely indebted to Blakeslee’s researches and

experiments on the Jimson weed (_Datura stramonium_). According to

Blakeslee, chromosomal mutants result from duplication, or from

reduction, of the chromosomes, and they are classified as _balanced_ or

_unbalanced_ types according as all, or only some, of the chromosomal

linkage-groups are similarly doubled or reduced. If only one of the

homologous chromosomes of a synaptic pair is doubled, the mutant

is termed a _triploid_ form. It is balanced when one homologous

chromosome is doubled in every synaptic pair, but if one or more

chromosomes be added to, or subtracted from, this balanced triploid

complex, the mutant is termed an unbalanced triploid. When all the

chromosomes of the normal diploid complex are uniformly doubled, we

have a balanced _tetraploid_ race. The subtraction or addition of

one or more chromosomes in the case of a balanced tetraploid complex

renders it an unbalanced tetraploid mutant. The retention in somatic

cells of the haploid number of chromosomes characteristic of gametes

and gametophytes gives a balanced _haploid_ mutant, from which hitherto

no unbalanced haploids have been obtained. The normal diploid type and

the balanced tetraploid type are said to constitute an _even_ balance,

while balanced triploids and haploids constitute an _odd_ balance. The

odd balances and all the unbalanced mutants are largely sterile. Thus,

for example, more than 80% of the pollen of the haploid mutant is bad.

“The normal Jimson Weed,” says Blakeslee, “is diploid (2n) with a total

of 24 chromosomes in somatic cells. In previous papers the finding of

tetraploids (4n) with 48 chromosomes and triploids (3n) with 36 was

reported, as well as unbalanced mutants with 25 chromosomes represented

by the formula (2n + 1). The finding of two haploid or 1n plants, which

we are now able to report, adds a new chromosomal type to the balanced

series of mutants in _Datura_. This series now stands: 1n, 2n, 3n, 4n.

Since a series of unbalanced mutants has been obtained from each of

the other balanced types by the addition or subtraction of one or more

chromosomes, it is possible that a similar series of unbalanced mutants

may be obtainable from our new haploid plants, despite the great

unbalance which would thereby result.” (_Science_, June 16, 1923, p.

646.) The haploid mutant, of which Blakeslee speaks, has, of course, 12

unpaired chromosomes in its somatic cells.

The balanced triploid is, like the haploid mutant, largely sterile,

and is only obtainable by crossing the tetraploid race with the normal

diploid plant. Since, then, the product of the cross of the diploid

and tetraploid races is sterile, the tetraploid race fulfills the

sterility test of a distinct species. Whether or not it fulfills

the endurance test of survival under natural condition is doubtful,

inasmuch as diploid Daturas are about three times as prolific as the

tetraploid race. Moreover, as Blakeslee himself confessed in a lecture

at Woods Hole attended by the present writer in the summer of 1923, the

origin of a balanced tetraploid form from the normal diploid type by

simultaneous duplication of all the chromosomes in the diploid complex,

is an event that has yet to be witnessed. Nor is any gradual transition

from the diploid to the tetraploid race, by way of unbalanced types

and triploids, conceivable, seeing that such forms are too sterile

to maintain themselves, and are, in fact, incapable of transmitting

their own type in the absence of artificial intervention. There are,

it is true, some instances, in which diploid and tetraploid races

and species occur together in cultivation and in nature. In certain

cases, this tetraploidy is merely apparent, being due to fragmentation

of the chromosomes; in other cases, it is really due to chromosomal

duplication, giving rise to genuine tetraploid forms. The question

is often hard to decide, the mere number of the chromosomes being

not, in itself, a safe criterion. Of the actual origin, however, of

tetraploid from diploid races we have as yet no observational evidence.

Hence Blakeslee’s researches on the chromosomal mutant have so far

failed to furnish experimental proof of the origin of a genuine new

species. Besides, waiving all other considerations, the limits within

which chromosomal duplication is possible are of necessity so narrow,

that, at best, this phenomenon can only be invoked to explain a very

small range of variation. In fact, it is doubtful whether haploidy,

triploidy, and tetraploidy have any important bearing whatever upon the

problem of the origin of species. (See Addenda.)

The mutation, then, in so far as we have experimental knowledge of it,

does not fulfill requirements of a specific change. It cannot even be

regarded as an _elementary step_ in the direction of such a change.

With this admission, De-Vriesianism becomes obsolete, descending like

its predecessors, Lamarckism and Darwinism, into the charnel-house of

discarded systems whose value is historic, but no longer scientific.

When we enquire into the reason of this common demise of all the

classic systems of transformism, we find it to reside in the progress

of the new science of Mendelian genetics, whose foundations were laid

by an Augustinian monk of the nineteenth century. Six years after

the appearance of Darwin’s “Origin of Species,” Gregor Johann Mendel

published a short paper entitled “Versuche über Pflanzen-hybriden,”

which, unnoticed at the time by a scientific world preoccupied with

Darwinian fantasies, was destined, on its coming to light at the

beginning of the present century, to administer the final _coup de

grace_ to all the elaborate schemes of evolution that had preceded or

followed its initial publication. It took half a century, however,

before the dust of Darwinian sensationalism subsided sufficiently, to

permit the “rediscovery” of Mendel’s solid and genuine contribution

to biological science. But the Prälat of the abbey at Brünn never

lived to see the day of his triumph. The true genius of his century,

he died unhonored and unsung, a pretender being crowned in his stead.

For Coulter says of Darwin: “He died April 19, 1882, probably the most

honored scientific man in the world.” (_Evolution_, 1916, p. 35.)

Within the small dimensions of the paper, of which we have spoken,

Mendel had compressed the results of years of carefully conceived and

accurately executed experimentation reduced to precise statistical

form and interpreted with a penetrating sagacity of the highest order.

It is no exaggeration to say that his discovery has revolutionized

the science of biology, giving it, for the first time, mathematical

formulas comparable to those of chemistry. His two laws of inheritance,

namely, the law of segregation and the law of independent assortment

of characters, have, as previously intimated, become the basis of the

new science of Genetics. His analysis of biparental reproduction has

interpreted for us the cytological phenomena of synapsis, meiosis, and

syngamy, has explained for us the instability of hybrids, has placed

Weismann’s speculations concerning the autonomy and continuity of the

germ plasm on a firm basis of experimental fact, has clarified all our

notions respecting the mode and range of hereditary transmission, and

has, in a word, opened our eyes to that new and hitherto unexplored

realm of nature which Bateson calls “the world of gametes.”

Efforts have been made to construct systems of transformism along

Mendelian lines, but none of them has met with notable success.

Lotsy, for example, sought to explain all variation on the basis of

the rearrangement of preëxistent genetic factors brought about by

crossing. But such a solution of the problem is very unsatisfactory.

In the first place, the generality of hybrid (heterozygous) forms are

ruled out on the score of instability. The phenotype of hybrids is

directly dependent, not on the genes themselves, but on the diploid

combination of genes contained in the zygote. This combination,

however, is always dissolved in the process of gamete-formation, by the

segregative reduction division which occurs in the reproductive organs

of the hybrid. Hybrids, therefore, do not _breed true_, if propagated

by sexual reproduction. To maintain constancy of type in hybrids, one

must resort to somatogenic reproduction (_i.e._ vegetative growth from

stems, etc.). Certain violets, in fact, as well as blackberries, are

maintained in a state of constant hybridism by means of this sort of

reproduction, even in nature. In the case of _balanced lethals_ (_i.e._

factors causing death in the pure or homozygous state), the hybrid

phenotype may be maintained even by sexual reproduction, inasmuch as

all the pure (homozygous) offspring are non-viable. Two lethals are

said to be balanced, when they occur, the first in one and the second

in the other homologous chromosome of the same synaptic pair. “Such a

factorial situation would maintain a state of constant heterozygosis,

the fixed hybridism of an impure species ... the hybrid will breed true

until the relative position of the lethals are changed by a crossover,

or the genetical constitution in these respects is altered by a

mutation.” (Davis, _Science_, Feb. 3, 1922, p. 111.) As is evident,

however, the condition of balanced lethals involves a considerable

reduction in fertility.

Hybridization, moreover, is successful between varieties of the same

species rather than between distinct species. Interspecific crosses

are in some cases entirely unproductive, in other cases productive

of wholly-sterile, hybrids, and in still other cases productive of

semisterile hybrids. When semisterile hybrids are obtainable from an

interspecific cross, the phenotype can be kept constant by somatogenic

reproduction, but, as we shall see in a later chapter, this kind of

reproduction does not counteract senescence, and stock thus propagated

usually plays out within a determinate period. Finally, the mixture

of incompatible germinal elements involved in an interspecific cross

tends to produce forms, which are subnormal in their viability and

vitality. The conclusions of Goodspeed and Clausen are the following:

“(1) As a consequence of modern Mendelian developments, the Mendelian

factors may be considered as making up a reaction system, the elements

of which exhibit more or less specific relations to one another; (2)

strictly Mendelian results are to be expected only when the contrast is

between factor differences within a common Mendelian reaction system

as is ordinarily the case in varietal hybrids; (3) when distinct

reaction systems are involved, as in species crosses, the phenomena

must be viewed in the light of a contrast between systems rather than

between specific factor differences, and the results will depend upon

the degree of mutual compatibility displayed between the specific

elements of the two systems.” (_Amer. Nat._, 51 (1917), p. 99.) To

these conclusions may be added the pertinent observation of Bradley

Moore Davis: “Of particular import,” he says, “is the expectation

that lethals most frequently owe their presence to the heterozygous

condition since the mixing of diverse germ plasms seems likely to lead

to the breaking down of delicate and vital adjustments in proportion

relative to the degree of protoplasmic confusion, and this means

chemical and physical disturbance.” (_Science_, Feb. 3, 1923, p. 111.)

But crossing produces, in the second filial generation (F₂), pure

(homozygous) as well as hybrid (heterozygous) forms.⅖ In some cases

these pure forms are new, the phenotype being different from that

of either pure grandparent. Such a result is produced by _random

assortment_ of the chromosomes in gamete and zygote formation, and

occurs when the genes for two or more pairs of contrasted characters

are located in different chromosome pairs. The phenomenon is formulated

in Mendel’s Second Law, the law of independent assortment. The novelty,

however, of the true-breeding forms thus produced is not absolute,

but relative. There is no origination of new hereditary factors. It

is simply a recombination of the old genes of different stocks, the

genes themselves undergoing no intrinsic alteration. The combination

is new, but not the elements combined. In addition to chromosomal

recombination, we have factorial recombination by means of crossovers.

This, too, can produce new and true-breeding forms of a fixed nature,

but here, likewise, it is the combination, and not the elements

combined, which is new. The “new” forms thus produced are called, as we

have seen, pseudomutants. When pseudomutations, that is, crossovers,

occur in conjunction with the condition of balanced lethals, they

closely simulate genuine factorial mutations. This is exemplified in

the case of De Vries’ _Œnothera Lamarckiana_, which is the product of

a crossover supervening upon a situation of balanced lethals. In cases

of this kind, the crossover releases hitherto suppressed recessive

characters, giving the appearance of real mutation. “The workers with

Drosophila,” says Davis, “seem inclined to believe that much of the

phenomena simulating mutation in their material is in reality the

appearance of characters set free by the breaking of lethal adjustments

which held the characters latent. Well-known workers have arrived at

similar conclusions for _Œnothera_ material and are not content to

accept as evidence of mutations the behavior of _Lamarckiana_ and some

other forms when they throw their marked variants.” (_Science_, Feb. 3,

1922, p. 111.)

The new forms, however, resulting from random assortment and crossovers

cannot be regarded as new species. “Analysis,” says Bateson, “has

revealed hosts of transferable characters. Their combinations suffice

to supply in abundance series of types which might pass for new

species, and certainly would be so classed if they were met with in

nature. Yet critically tested, we find that they are not distinct

species and we have no reason to suppose any accumulation of characters

of the same order would culminate in the production of distinct

species. Specific difference therefore must be regarded as probably

attaching to the base upon which these transferables are implanted, of

which we know absolutely nothing at all. Nothing that we have witnessed

in the contemporary world can colorably be interpreted as providing the

sort of evidence required.” (_Science_, Jan. 20, 1922, pp. 59, 60.)

Anyone thoroughly acquainted with the results of genetical analysis and

research will find it impossible to escape the conviction that there

is no such thing as experimental evidence for evolution. In spite of

the enormous advances made in the fields of genetics and cytology,

the problem of the origin of species is, scientifically speaking,

as mysterious as ever. No variation of which we have experience is

interpretable as the transmutation of a specific type, and David Starr

Jordan voices an inevitable conclusion when he says: “None of the

created ‘new species’ of plant or animal I know of would last five

years in the open, nor is there the slightest evidence that any new

species of field or forest or ocean ever originated from mutation,

discontinuous variation, or hybridization.” (_Science_, Oct. 20, 1922,

p. 448.)

“In any case,” as Professor Caullery tells us in his Harvard lecture

on the “Problem of Evolution,” “we do not see in the facts emerging

from Mendelism, how evolution, in the sense that morphology suggests,

can have come about. And it comes to pass that some of the biologists

of greatest authority in the study of Mendelian heredity are led, with

regard to evolution, either to a more or less complete agnosticism,

or to the expression of ideas quite opposed to those of the preceding

generation; ideas which would almost take us back to creationism.”

(Smithson. Inst. Rpt. for 1916, p. 334.) It is, of course, impossible

within the limits of a single chapter to convey any adequate impression

of all that Mendel’s epoch-making achievement portends, but what

has been said is sufficient to give some idea of the acuteness of

the crisis through which the theory of organic evolution is passing

as a result of his discovery. In its classic forms of Lamarckism,

Darwinism and De-Vriesianism, the survival of the theory is out of the

question. Whether or not it can be rehabilitated in any form whatever

is a matter open to doubt. Transfixed by the innumerable spears of

modern objections, its extremity calls to mind the plight of the Lion

of Lucerne. Possibly, it is destined to find a rescuer in some great

genius of the future, but of one thing, at least, we may be perfectly

certain, namely, that, even if rejuvenated, it will never again resume

the lineaments traced by Charles Darwin. In the face of this certainty,

it is almost pitiful to hear the die-hards of Darwinism bolstering up a

lost cause with the wretched quibble that, though natural selection has

been discredited as an explanation of the differentiation of species,

Darwinism “in its essentials” survives intact. For, if there is any

feature which, beyond all else, deserves to be called an essential of

Darwin’s system, surely it is natural selection. For Darwin it was “the

most important” agency of transformation (cf. “Origin of Species,”

6th ed., p. 5). Apart from his hypothesis of the summation through

inheritance of slight variations (“fluctuations”), now completely

demolished by the new science of genetics, it represented his sole

contribution to the philosophy of transformism. It alone distinguishes

Darwinism from Lamarckism, its prototype. Without it the “Origin of

Species” would be Hamlet without the Prince of Denmark. With it

Darwin’s fame should stand or fall. Therefore, since Darwin erred in

making it “the most important means of modification,” Darwinism is

dead, and no grief of mourners can resuscitate the corpse. “Through

the last fifty years,” says Bateson, “this theme of the natural

selection of favored races has been developed and expounded in writings

innumerable. Favored races certainly can replace others. The argument

is sound, but we are doubtful of its value. For us that debate stands

adjourned. We go to Darwin for his incomparable collection of facts.

We would fain emulate his scholarship, his width, and his power of

exposition, but to us he speaks no more with philosophical authority.

We read his scheme of evolution as we would those of Lucretius or

of Lamarck, delighting in their simplicity and their courage.”

(_Heredity_, Presid. Add. to British Assoc. for Advanc. of Science,

Smith. Inst. Rpt. for 1915, p. 365.)

CHAPTER II

HOMOLOGY AND ITS EVOLUTIONARY INTERPRETATION

The recent revival of interest in the problem of evolution seems to

have called forth two very opposite expressions of opinion from those

who profess to represent Catholic thought on this subject. M. Henri

de Dorlodot, in his “Le Darwinisme,” appears in the rôle of an ardent

admirer of Darwin and an enthusiastic advocate of the doctrine of

Transformism. The contrary attitude is adopted by Mr. Alfred McCann,

whose “God—or Gorilla” is bitterly antagonistic not only to Darwinism

but to any form whatever of the theory of Transformism. Both of these

works possess merits which it would be unjust to overlook. Dorlodot

deserves credit for having shown conclusively that there is absolutely

nothing in the Scriptures, or in Patristic tradition, or in Catholic

theology, or in the philosophy of the Schools, which conflicts with

our acceptance of organic evolution as an hypothesis explanatory of

certain biological facts. In like manner, it must be acknowledged that,

even after a liberal discount has been made in penalty of its bias and

scientific inaccuracy, Mr. McCann’s book still contains a formidable

residue of serious objections, which the friends of evolution will

probably find it more convenient to sidestep than to answer.

Unfortunately, however, neither of these writers maintains that

balanced mental poise which one likes to see in the defenders of

Catholic truth. Dorlodot seems too profoundly impressed with the

desirability of occupying a popular position to do impartial justice

to the problem at issue, and his anxiety to keep in step with the

majority blinds him apparently to the flaws of that “Darwinism”

which he praises. Had he been content with a simple demarcation of

negative limits, there would be no ground for complaint. But, when

he goes so far as to bestow unmerited praise upon the author of the

mechanistic “Origin of Species” and the materialistic “Descent of

Man”; when, by confounding Darwinism with evolution, he consents

to that historical injustice which allows Darwin to play Jacob to

Lamarck’s Esau, and which leaves the original genius of Mendel in

obscurity while it accords the limelight of fame to the unoriginal

expounder of a borrowed conception; when, by means of the sophistry of

anachronism, he speciously endeavors to bring the speculations of an

Augustine or an Aquinas into alignment with those of the ex-divinity

student of Cambridge; when he assumes that Fixism is so evidently wrong

that its claims are unworthy of consideration, whereas Transformism

is so evidently right that we can dispense with the formality of

examining its credentials; when, in a word, he expresses himself not

merely in the sense, but in the very stereotyped cant phrases of a

dead philosophy, we realize, with regret, that his conclusions are

based, not on any reasoned analysis of the evidence, but solely upon

the dogmatism of scientific orthodoxy, that his thought is cast in

antiquated molds, and that for him, apparently, the sixty-five years

of discovery and disillusionment, which have intervened since the

publication of the “Origin of Species,” have passed in vain.

But, if Dorlodot represents the extreme of uncritical approval, Mr.

McCann represents the opposite, and no less reprehensible, extreme of

biased antagonism, that is neither fair in method nor conciliatory in

tone. Instead of adhering to the time-honored practice of Catholic

controversialists, which is rather to overstate than to understate the

argument of an adversary, Mr. McCann tends, at times, to minimize, in

his restatement, the force of an opponent’s reasoning. He frequently

belittles with mere flippant sneer, and is only too ready to question

the good faith of those who do not share his convictions. Thus, when

McCann ridicules Wells and accuses him of pure romancing, because the

latter speaks of certain hairy “wild women” of the Caves, he himself

seems to be ignorant of the fact that a palæolithic etching has been

found representing a woman so covered with hair that she had no need of

other apparel (the bas-relief from Laugerie-Basse carved on reindeer

palm—cf. Smithson. Inst. Rpt. for 1909, p. 540 and Plate 2).

Mr. McCann may object, with truth, that this is far from being a

proof that the primitive representatives of the human race were hairy

individuals, but the fact suffices, at least, to acquit Mr. Wells of

the charge of unscrupulous invention. Hence, while we have no wish

to excuse the lamentable lack of scientific conscientiousness so

manifestly apparent in the writings of popularizers of evolution, like

Wells, Osborn, and Haeckel, nevertheless common justice, not to speak

of charity, constrains us to presume that, occasionally at least, their

departures from the norm of objective fact were due to ordinary human

fallibility or to the mental blindness induced by preconceptions,

rather than to any deliberate intent to deceive. And we feel ourselves

impelled to make this allowance for unconscious inaccuracy all the

more readily that we are confronted with the necessity of extending

the selfsame indulgence to Mr. McCann himself. Thus we find that the

seventh illustration in “God—or Gorilla” (opposite p. 56) bears the

legend: “Skeletons of man and _chimpanzee_ compared,” when, in point

of fact, the ape skeleton in question is not that of a chimpanzee

(_Troglodytes niger_) at all, but of an Orang-utan (_Simia satyrus_),

as the reader may verify for himself by consulting Plate VI of the

English version of Wasmann’s “Modern Biology,” where the identical

illustration appears above its proper title: “Skeleton of an adult

Orang-utan.” Since the error is repeated in the index of illustrations

and in the legend of the third illustration of the appendix, it is

impossible, in this instance, to shift the responsibility from Mr.

McCann to the printer. In any case, it is sincerely to be hoped that

this, and several other infelicitous errors will be rectified in the

next edition of “God—or Gorilla.”

In the next chapter we shall have occasion to refer again to Dorlodot’s

book. For the present, however, his work need not concern us, while

in that of Mr. McCann we single out but one point as germane to our

subject, namely, the latter’s inadequate rebuttal of the evolutionary

argument from homology. The futility of his method, which consists in

matching insignificant differences against preponderant resemblances,

and in exclaiming with ironic incredulity: “Note extraordinary

resemblances!” becomes painfully evident, so soon as proper

presentation enables us to appreciate the true force of the argument he

is striving to refute. _Functionally_ the foot of a Troglodyte ape may

be a “hand,” but _structurally_ it is the homologue of the human foot,

and not of the human hand; nor is this homology effectually disposed

of by stressing the dissimilarity of the hallux, whilst one remains

discreetly reticent concerning the similarity of the calcaneum. For

two reasons, therefore, the irrelevance of Mr. McCann’s reply is of

special interest here: (1) because it illustrates concretely the danger

of rendering a refutation inconsequential and inept by failing to plumb

the full depth of the difficulty one is seeking to solve; (2) because

it shows that it is vain to attempt to remove man’s body from the scope

of this argument by citing the inconsiderable structural differences

which distinguish him from the ape, so that, unless the argument from

homology proves upon closer scrutiny to be inherently _inconclusive_,

its applicability to the human body is a foregone conclusion, and

implies with irresistible logic the common ancestry of men and apes.

Such are the reflections suggested by the meager measure of justice

which Mr. McCann accords to the strongest zoölogical evidence in favor

of evolution, and they contain in germ a feasible program for the

present chapter, which, accordingly, will address itself: first, to the

task of ascertaining the true significance of homology in the abstract

as well as the full extent of its application in the concrete; second,

to that of determining with critical precision its intrinsic value as

an argument for the theory of transmutation.

_Homology_ is a technical term used by the systematists of botany,

zoölogy and comparative anatomy to signify basic structural similarity

as distinguished from superficial functional similarity, the latter

being termed _analogy_. Organisms are said to exemplify the phenomenon

of homology when, beneath a certain amount of external diversity, they

possess in common a group of correlated internal resemblances of such a

nature that the organisms possessing them appear to be constructed upon

the same fundamental plan. In cases of this kind, the basic similarity

is frequently masked by a veneer of unlikeness, and it is only below

this shallow surface of divergence that we find evidences of the

identical structure or common type.

Thus organs of different animals are said to be homologous when they

are composed of like parts arranged in similar relation to one another.

Homologous organs correspond bone for bone and tissue for tissue, so

that each component of the one finds its respective counterpart in

the other. The organs in question may be functionally specialized

and externally differentiated for quite different purposes, but the

superficial diversity serves only to emphasize, by contrast, the

underlying identity of structure which persists intact beneath it.

Thus, for example, the wing of a pigeon, the flipper of a whale, the

foreleg of a cat, and the arm of a man are organs differing widely in

function as well as outward appearance, but they are called homologous,

none the less, because they all exhibit the same basic plan, being

composed of similar bones similarly disposed with respect to one

another.

Organs, on the other hand, are called analogous which, though

fundamentally unlike in structure, are, nevertheless, superficially

modified and specialized for one and the same function. The wing of

a bird and the wing of an insect furnish a trite instance of such

analogy. Functionally they subserve the same purpose, but structurally

they bear no relation to each other. In like manner, though both are

devoted to the same function, there exists between the leg of a man and

the leg of a spider a fundamental disparity in structure.

At times, specialization for the selfsame function involves the

emergence of a similar modification or uniform structural adaptation

from a substrate of basic dissimilarity. In these instances of parallel

modifications appearing on the surface of divergent types, we have

something more than mere functional resemblance. Structure is likewise

involved, albeit superficially, in the modification which brings

about this external uniformity. In such cases, analogy is spoken of

as _convergence_, a phenomenon of which the mole and the mole-cricket

constitute a typical example. The burrowing legs of the insect are,

so far as outward appearance goes, the exact replica on a smaller

scale of those of the mole, though, fundamentally, their structure is

quite unlike, the mole being built on the endoskeletal plan of the

vertebrates, whereas the mole-cricket is constructed on the exoskeletal

plan characteristic of the arthropods. Speaking of the first pair of

legs of the mole-cricket, Thomas Hunt Morgan says: “By their use the

mole-cricket makes a burrow near the surface of the ground, similar

to, but of course much smaller than, that made by the mole. In both

of these cases the adaptation is the more obvious, because, while the

leg of the mole is formed on the same general plan as that of other

vertebrates, and the leg of the mole-cricket has the same fundamental

structure as that of other insects, yet in both cases the details of

structure and the general proportions have been so altered that the

leg is fitted for entirely different purposes from those to which the

legs of other vertebrates and other insects are put.” (Quoted by Dwight

in “Thoughts of a Catholic Anatomist,” p. 235.) In the analogies of

convergence, therefore, we have the exact converse of the phenomenon so

often encountered in connection with homology. The latter exhibits a

contrast between basic identity and superficial diversity, the former a

contrast between superficial convergence and fundamental divergence.

Now the extreme importance of homology is manifest from the fact that

the taxonomists of zoölogy and botany have found it to be the most

satisfactory basis for a scientific classification of animals and

plants. In both of these sciences, organisms are arranged in groups

according as they possess in common certain points of resemblance

whereby they may be referred to this, or that, general type. The

resemblance is most complete between members of the same species, which

do not differ from one another by any major difference, though they may

exhibit certain minor differences justifying their subdivision into

varieties or races. These morphological considerations, however, must,

in the case of an organic species, be supplemented by the additional

physiological criteria of perfect sexual compatibility and normal

viability, as we have already had occasion to note in the previous

chapter. When organisms, though distinguished from one another by

some major difference, agree, notwithstanding, in the main elements

of structure, the several species to which they belong are grouped

under a common genus, and similarly genera are grouped into families.

A _relative_ major difference, such as a difference in the size of

the teeth, suffices for the segregation of a new species, while an

_absolute_ difference, such as a difference in the number of teeth or

the possession of an additional organ, suffices for the segregation of

a new genus. In practice, however, the classifications of systematists

are often very arbitrary, and we find the latter divided into two

factions, the “lumpers” who wish to reduce the number of systematic

groups and the “splitters” who have a passion for breaking up larger

groups into smaller ones on the basis of tenuous differences. Above

the families are the orders, and they, in turn, are assembled in still

larger groups called classes, until finally we reach the phyla or

branches, which are the supreme categories into which the plant and

animal kingdoms are divided. As we ascend the scale of classification,

the points of resemblance between the organisms classified are

constantly decreasing in number, while the points of difference

increase apace. Hence, whereas members of the same species have very

much in common, members of the same phylum have very little in common,

and members of different phyla show such structural disparity that

further correlation on the basis of similarities becomes impossible

(in the sense, at least, of a reliable and consistent scheme of

classification), all efforts to relate the primary phyla to one another

in a satisfactory manner having proved abortive.

Within the confines of each phylum, however, homology is the basic

principle of classification. But the scientist is not content to note

the bare fact of its existence. He seeks an explanation, he wishes to

know the _raison d’être_ of homology. Innumerable threads of similarity

run through the woof of divergence, and the question arises: How can

we account for the coëxistence of this woof of diversity with a warp

of similarity? Certainly, if called upon to explain the similarity

existent between members of one and the same species, even the man in

the street would resort instinctively to the principle of inheritance

and the assumption of common ancestry, exclaiming: “Like sire, like

son!” It is a notorious fact that children resemble their parents,

and since members of the same species are sexually compatible and

perfectly interfertile, there is no difficulty whatever in the way of

accepting the presumption of descent from common ancestral stock as a

satisfactory solution of the problem of specific resemblance. Now, it

is precisely this selfsame principle of heredity which the Transformist

invokes to account for generic, no less than for specific, similarity.

In fact, he presses it further still, and professes to see therein

the explanation of the resemblances observed between members of the

different families, orders, and classes, which systematists group

under a common phylum. This, of course, amounts to a bold extension of

the principle of inheritance far beyond the barriers of interspecific

sterility to remote applications that exceed all possibility of

experimental verification. Transformists answer this difficulty,

however, by contending that the period, during which the human race

has existed, has been, geologically speaking, all too brief, and

characterized by environmental conditions much too uniform, to afford

us a favorable opportunity for ascertaining the extreme limits to which

the genetic process may possibly extend; and, even apart from this

consideration, they say, racial development (phylogeny) may be, like

embryological development (ontogeny) an irreversible process, in which

case no recurrence whatever of its past phenomena are to be expected in

our times.

Be that as it may, the evolutionist interprets the resemblances of

homology as surviving vestiges of an ancient ancestral type, which

have managed to persist in the descendants notwithstanding the

transformations wrought in the latter by the process of progressive

divergence. Moreover, just as the existence of a common ancestor is

inferred from the _fact_ of resemblance, so the relative position

in time of the common ancestor is inferred from the _degree_ of

resemblance. The common ancestor of forms closely allied is assumed to

have been proximate, that of forms but distantly resembling each other

is thought to have been remote. Thus the common ancestor of species

grouped under the same genus is supposed to have been less remote

than the common ancestor of all the genera grouped under one family.

The same reasoning is applied, _mutatis mutandis_, to the ancestry of

families, orders and classes.

The logic of such inferences may be questioned, but there is no

blinking the fact that, in practice, the genetic explanation of

homology is assumed by scientists to be the only reasonable one

possible. In fact, so strong is their confidence in the necessity of

admitting a solution of this kind, that they do not hesitate to make it

part and parcel of the definition of homology itself. For instance, on

page 130 of Woodruff’s “Foundations of Biology” (1922), we are informed

that homology signifies “a fundamental similarity of structure based on

descent from a common antecedent form.” The Yale professor, however,

has been outdone in this respect by Professor Calkins of Columbia, who

discards the anatomical definition altogether and substitutes, in lieu

thereof, its evolutionary interpretation. “When organs have the same

ancestry,” he says, “that is, when they come from some common part of

an ancestral type, they are said to be homologous.” (“Biology,” p.

165.) In short, F. A. Bather is using a consecrated formula culled from

the modern biological creed when he says: “The old form of diagnosis

was _per genus et differentiam_. The new form is _per proavum et

modificationem_.” (_Science_, Sept. 17, 1920, p. 259.)

A moment’s reflection, however, will make it clear that, in thus

confounding the definition proper with its theoretical interpretation,

the modern biologist is guilty of a logical atrocity. Homology, after

all, is a simple anatomical fact, which can be quite adequately

defined in terms of observation; nor is the definition improved in

the least by having its factual elements diluted with explanatory

theory. On the contrary, the definition is decidedly weakened by such

redundancy. And as for those who insist on defining homology in terms

of atavistic assumption instead of structural affinity, their procedure

is tantamount to defining the clear by means of the obscure, an actual

effect by means of a possible cause. Moreover, this attempt to load

the dice in favor of Transformism by tampering with the definition of

homology ends by defeating its own purpose. For, if homology is to

serve as a legitimate argument for evolution, then obviously evolution

must not be included in its definition; otherwise, the conclusion is

anticipated in the premise, the question is begged, and the argument

itself rendered a vicious circle.

Having formed a sufficiently clear conception of homology as a

static fact, we are now in a position to consider the problem of its

causality with reference to the solution proposed by evolutionists.

Transmutation, they tell us, results from the interaction of a

twofold process, namely, the conservative and similifying process

called _inheritance_, and progressive and diversifying process known

as _variation_. Inheritance by transmitting the ancestral likeness

tends to bring about uniformity. Variation by diverting old currents

into new channels adjust organisms to new situations and brings about

modification. Homology, therefore, is the effect of inheritance, while

adaptedness or modification is the product of variation.

As here used, the term inheritance denotes something more than a mere

recurrence of parental characters in the offspring. It signifies a

process of genuine transmission from generation to generation. Strictly

speaking, it is not the _characters_, such as coloration, shape, size,

chemical composition, structural type, and functional specificity, that

are “inherited,” but rather the hereditary _factors_ or chromosomal

_genes_, which are actually transmitted, and of which the characters

are but an external expression or manifestation. Hence, it is scarcely

accurate to speak of “inherited,” as distinguished from “acquired,”

characters. As a matter of fact, all somatic characters are joint

products of the interaction of germinal and environmental factors.

Consequently, the external character would be affected no less by a

change in the environmental factors than by a change in the germinal

factors. In a word, somatic characters are not the exclusive expression

of the genetic factors, but are equally dependent upon environmental

influence, and hence it is only to the extent that these characters

are indicative of the specific constitution of the germ plasm that

we may speak of them as “inherited,” remembering that what is really

transmitted to the offspring is a complex of genes or germinal

factors, and not the characters themselves. The sense is, therefore,

that “inherited” characters are manifestative of what is contained

in the germ plasm, whereas “acquired” characters have no specific

germinal basis, but are a resultant of the interaction between the

somatic cells and the environment. In modern terminology, as we have

seen, the aggregate of germinal factors transmitted in the process of

reproduction is called the genotype, while the aggregate of somatic

characters which manifest these germinal factors externally is spoken

of as the phenotype. Only the genotype is transmitted, the phenotype

being the subsequent product of the interplay of genetic factors and

environmental stimuli, dependent upon, and expressive of, both.

Variation, therefore, may be based upon a change in the germ plasm,

or in the environment, or in both. If it rests exclusively upon an

extraordinary change in the environmental conditions, the resulting

modification is non-inheritable, and will disappear so soon as the

exceptional environmental stimulus that evoked it is withdrawn. If,

on the contrary, it is based upon a germinal change, it will manifest

itself, even under ordinary, i.e. unchanged or uniform environmental

influence. In this case, the modification is inheritable in the sense

that it is the specific effect of a transmissible germinal factor,

which has undergone alteration.

As we have seen in the foregoing chapter, there are three kinds of

germinal change which result in “inheritable” modifications. The

first is called factorial mutation, and is initiated by an alteration

occurring in one or more of the chromosomal genes. The second is called

chromosomal mutation, and is caused by duplication (or reduction) of

the chromosomes. The third may be termed recombination, one type of

which results from the crossover or exchange of genes between pairing

chromosomes (“pseudomutation”), the other from random assortment in

accordance with the Mendelian law of the independence of allelomorphic

pairs. This so-called “random assortment of the chromosomes” is the

result of the shuffling and free deals of the chromosomal cards of

heredity which take place twice in the life-cycle of organisms:

viz. first, in the process of gametic reduction (meiosis); second,

in the chance meeting of variously-constituted sperms and eggs in

fertilization. A mischance of the first of these “free deals” is

bewailed in the following snatch from a parody belonging to the Woods

Hole anthology.

“Oh chromosomes, my chromosomes,

How sad is my condition!

My grandsire’s gift for writing well

Has gone to some lost polar cell

And so I write this doggerel,

I cannot do much better.”

These kinds of variation, however, in so far as they fall within the

range of actual observation, are confined within the limits of the

organic species. Intra-specific variation, however, will not suffice.

To account for the adaptive modifications superimposed upon underlying

structural identity, Transformism is obliged to assume the possibility

of trans-specific variation. Yet in none of the foregoing processes of

variation do we find a valid factual basis for this assumption.

Factorial mutation, for instance, waiving its failure to produce

naturally-viable forms, or to meet the physiological sterility test

of a new species, admits of interpretation as a change of loss due

to the “dropping out” of a gene from the germinal complex. Bateson’s

conception of evolution as a process consisting in the gradual loss of

inhibitive genes, whose elimination releases suppressed potentialities,

seems rather incredible. Many will be inclined to see in Castle’s

facetious epigram a _reductio ad absurdum_ of Bateson’s suggestion;

for, according to the latter’s view, as the Harvard professor remarks,

we should have to regard _man_ as _a simplified amœba_. Certainly,

it seems nothing short of a contradiction to ascribe the progressive

complication of the phenotype to a simplification of the genotype by

loss.

On the other hand, not only is there no experimental evidence of a

germinal change by positive acquisition, that is, by the addition of

genes, but it is hard to conceive how such a change could come about.

“At first,” admits Bateson, “it may seem rank absurdity to suppose

that the primordial form or forms of protoplasm could have contained

complexity enough to produce the divers types of life.” “But,” he

asks, “is it easier to imagine that these powers could have been

conveyed by extrinsic addition? Of what nature could these additions

be? Additions of material can not surely be in question. We are told

that salts of iron in the soil may turn a pink hydrangea blue. The

iron cannot be passed on to the next generation. How can iron multiply

itself? The power to assimilate iron is all that can be transmitted. A

disease-producing organism like the pebrine of silkworms can in a very

few cases be passed on through the germ cells. But it does not become

part of the invaded host, and we can not conceive it taking part in the

geometrically ordered processes of segregation. These illustrations

may seem too gross; but what refinement will meet the requirements of

the problem, that the thing introduced must be, as the living organism

itself is, capable of multiplication and of subordinating itself in a

definite system of segregation?” (_Heredity_, Smithson. Inst. Rpt. for

1915, p. 373.)

Nor can we agree with Prof. T. H. Morgan’s contention that the

foregoing difficulty of Bateson has been solved by the discovery of

the chromosomal mutation. All unbalanced chromosomal mutants are

subnormal in their viability and vitality, not to speak of their marked

sterility. Haploidy represents a regressive, rather than a progressive,

step. The triploid mutant is sterile. The tetraploid race of Daturas

is inferior in fertility to the normal diploid plant. The origin of

balanced tetraploidy from diploidy must be presumed, since it has never

been observed. Moreover, tetraploidy represents only quantitative, and

not qualitative, progress. The increased mass of the nucleus produces

an enlargement of the cytoplasm, the result of which is giantism. This

effect, however, is not specific; for giant and normal races possessing

each the same number of chromosomes are known to exist in nature. Hence

giantism may be due to other causes besides chromosomal duplication.

The only effect of this doubling is a reinforcement and intensification

of the former effect of the genetic factors, their specificity

remaining unchanged. Double doses are substituted for single doses of

the factors, but nothing really new is added. Morgan himself recognizes

that this mere repetition of identical genes is insufficient, and that

their multiplication must be qualitative as well as numerical, to

answer the specifications of a progressive step in evolution. Hence he

suggests that the chromosomal mutation is subsequently supplemented by

appropriate factorial mutation. Once this supposition is made, however,

all the objections we have mentioned in connection with factorial

mutation (_e.g._ the subnormality of its products, its intra-specific

nature, etc.) return to plague the speculator, and, in addition to

these, he is confronted with the new difficulty of explaining how the

redundance of duplicate genes can be removed and replaced by coördinate

differentiation in their respective specificities. Now we have no

factual evidence whatever of such a solidaric redifferentiation of the

germinal factors, that would modify harmoniously the composition and

rôle of each and every gene in the factorial complex. Nor is there

any possibility whatever of accounting for this telic superregulation

of the germinal regulators upon a purely mechanistic basis. How can

the ultimate chemical determinants of heredity be thus redetermined?

Consequently, although there is gametic incompatibility between diploid

races and the tetraploid races, which are said to have arisen from

the former, we are not, nevertheless, warranted, by what has been

experimentally verified, in regarding tetraploid races as new species,

or as progressive steps in the process of organic evolution.

To conclude, therefore, we have experimental verification of the

efficacy of the similifying process said to have been at work in

evolution, namely, inheritance. The same, however, cannot be said of

the correlative diversifying process of trans-specific variation, which

is said to have superficially modified old structures into new species.

The latter process, accordingly, is but a pure postulate of science

known to us only through the effect hypothetically assigned to it,

namely, the adaptive modification.

The adaptation, however, of which there is question here is not to be

confounded with the “acquired adaptation” of Lamarckian fame; for,

unlike the latter, it is an inheritable modification rooted in the germ

plasm. Adaptations of this sort do, indeed, adjust the organism to

its external environment, but they are innate and not acquired. Hence

they are often spoken of as _preadaptations_; for they precede, in a

sense, the organism’s contact with the environing element to which

they adjust it. They may possibly, it is true, have been acquired in

the distant past, but they have now a specific germinal foundation,

and no one was ever privileged to witness their initial production _de

novo_. The whale, for example, though fundamentally a warm-blooded

mammal, is superficially a fish, by reason of such a preadaptation

to its marine environment. Preadaptation is of common occurrence,

especially among parasites, symbiotes, commensals, and inquilines.

Wasmann cites innumerable instances of beetles and flies so profoundly

modified, in accommodation to their mode of life as guests in termite

nests, that the systematist hesitates to classify them under any of the

accepted orders of insects. Here the adaptive modification so disturbs

the underlying homology as to make of these creatures taxonomical

ambiguities. In the case of _Termitomyia_, he tells us, “the whole

development of the individual has been so modified that it resembles

that of a viviparous mammal rather than that of a fly.” (“The Problem

of Evolution,” pp. 14, 15.)

Such modifications, however, amount to major, and not merely minor,

differences. We are not dealing, therefore, with varietal distinctions

here, but with specific, generic, and even ordinal differences. With

reference to the phenomenon of adaptive modification,[3] three things,

consequently, are worthy of note: (1) it has the semblance of being

adventitious to the underlying structural uniformity; (2) it is of

such magnitude that it cannot be ascribed to variation within the

species; (3) it has been appropriated by the hereditary process, in the

sense that it is now an “inherited” character based on the transmission

of specific germinal factors.

[3] It may be remarked, in passing, that experimental genetics

and mutation furnish no clue to the origin of adaptive

characters. The Lamarckian idea alone gives promise in this

direction. Orthogenesis leaves unsolved the mystery of

preadaptation; yet only orthogenetic systems of evolution can

be constructed on the basis of genetical facts. “Mutations

and Mendelism,” says Kellogg, “may explain the origin of new

species in some measure, but they do not explain adaptation in

the slightest degree.” (_Atlantic Monthly_, April, 1924, pp.

488, 489.) We have seen in the previous chapter that they are

impotent to explain in _any_ measure the origin of new species.

Now it is claimed that for the occurrence of this kind of modification

in conjunction with homology only one rational explanation is

possible, and that explanation is evolution. If this contention be a

sound one, and Dorlodot, who claims certitude for the evolutionary

solution, insists that it is such, then, in the name of sheer

logical consistency, but one course lies open to us. We cannot stop

at Wasmann’s comma,[4] we must press on to the very end of the

evolutionary sentence and sing with the choristers of Woods Hole:

[4] Rev. Erich Wasmann, S. J., accepts the evolutionary

inference from homology as regards _plants_ and _animals_. When

it comes to _man_, however, he attempts to draw the line, and

argues painstakingly against the assumption of a bestial origin

of the human body.

“It’s a long way from Amphioxus,

It’s a long way to us;

It’s a long way from Amphioxus,

To the meanest human cuss.

Good-bye fins and gill slits;

Welcome skin and hair.

It’s a long, long way from Amphioxus,

But we came from there.”

In this predicament it will not do, as we shall see presently, to adopt

Mr. McCann’s expedient of balancing anatomical differences against

anatomical resemblances. To do so is to court certain and ignominious

defeat. We must, therefore, examine the argument dispassionately. If it

be solid, we must accept it and give it general application. If it be

unsound, we must detect its flaws and expose them. Intellectual honesty

allows us no alternative!

Moreover, in weighing the argument from organic homology we must not

lose sight of the two important considerations previously stressed:

(1) that the inference of common ancestry in the case of homologous

forms is based, not upon this or that particular likeness, but upon an

entire group of coördinated resemblances; (2) that the resemblances

involved are not exterior similarities, but deep-seated structural

uniformities perfectly compatible with diversities of a superficial and

functional character. “Nothing,” says Dr. W. W. Keen, “could be more

unlike externally than the flipper of a whale and the arm of a man.

Yet you find in the flipper the shoulderblade, humerus, radius, ulna,

and a hand with the bones of four fingers masked in a mitten of skin.”

(_Science_, June 9, 1922, p. 605.)

In fact, the resemblances may, in certain instances, be so deeply

submerged that they no longer appear in the adult organism at all and

are only in evidence during a transitory phase of the embryological

process. In such cases, the embryo or larva exhibits, at a particular

stage, traces of a uniformity completely obliterated from the adult

form. In short, though frequently presented as a distinct argument,

embryological similarity, together with all else of value that can

still be salvaged from the wreck of the Müller-Haeckel Law of Embryonic

Recapitulation, is, at bottom, identical with the general evolutionary

argument from homology. In the latter argument we are directed to

look beneath the modified surface of the adult organism for surviving

vestiges of the ancestral type. In the former, we are bidden to go

deeper still, to the extent, that is, of descending into the very

embryological process itself, in order to discover lingering traces

of the ancestral likeness, which, though now utterly deleted from the

transformed adult, are yet partially persistent in certain embryonic

phases.

In sectioning a larval specimen of the fly-like termite-guest known

as _Termitoxenia Heimi_, Father Wasmann came across a typical

exemplification of this embryological atavism. In the adult insect, a

pair of oar-like appendages replace the wings characteristic of the

_Diptera_ (flies). These appendages are organs of exudation, which

elaborate a secretion whereof the termites are very fond, and thereby

render their possessors welcome guests in the nests of their hosts. The

appendages, therefore, though now undoubtedly inherited characters,

are the specific means by which these inquilines are adapted to their

peculiar environment and mode of life among the termites. Moreover, the

organs in question not only differ from wings functionally, but, in the

adult, they bear no structural resemblance whatever to the wings of

flies. Nevertheless, on examining his sections of the above-mentioned

specimen, Wasmann found a developmental stage of brief duration during

which wing veins appeared in the posterior branches of the embryonic

appendages. Now, assuming that Wasmann’s technique was faultless,

his specimen normal, and his interpretation correct, it is rather

difficult to avoid his conclusion that we have here, in this transitory

larval phase, the last surviving vestige of ancestral wings now wholly

obliterated from the adult type, that, consequently, this wingless

termite guest is genetically related to the winged _Diptera_, and that

we must see in the appendages aboriginal wings diverted from their

primitive function and respecialized for the quite different purpose of

serving as organs of exudation, (cf. “Modern Biology,” p. 385.) Indeed,

phenomena of this kind seem to admit of no other explanation than the

atavistic one. It should be remembered, however, that Wasmann does not

appear to have verified the observation in more than one specimen,

and that a larger number of representative specimens would have to be

accurately sectioned, strained, examined and interpreted, before any

reliable conclusion could be drawn.[5]

[5] This transitory lymphatic, or tracheal venation appearing

in the appendages at the stenogastric stage may not have the

particular significance that Father Wasmann assigns. Such

venation, even if vestigial and aborted, need not necessarily

be a vestige of former _wing_ venation. To demonstrate the

validity of the atavistic interpretation, all other possible

interpretations would have to be definitively excluded.

Such, in its most general aspect, is the atavistic solution of the

problem presented by the homology of types. In it, similarity and

diversity are harmoniously reconciled, in the sense that they affect,

respectively, different structural, or different developmental, levels.

It is futile, therefore, to look for contradictions where they do not

exist. In a word, the attempt to create opposition between a group of

basic and correlated uniformities, on the one hand, and some particular

external difference, on the other, is not only abortive, but absolutely

irrelevant as well. The reason is obvious. Only when likeness is

associated with unlikeness is it an argument for Transmutation.

Likeness alone would demonstrate Immutability by indicating a process

of pure inheritance as distinguished from the process of variation.

Hence evolutionists do not merely concede the coëxistence of diversity

with similarity, they gladly welcome this fact as vitally necessary to

their contention.

Now it is precisely this point which Mr. McCann, like many other

critics of evolution, fails utterly to apprehend. Consequently, his

efforts to extricate the human foot from the toils of simian homology

are entirely unavailing. To offset the force of the argument in

question, it is by no means sufficient, as he apparently imagines, to

point to the fact that, unlike the hallux of the ape, the great toe in

man is non-opposable (cf. “God—or Gorilla,” pp. 183, 184, and legends

under cuts opposite pp. 184 and 318). The evolutionist will reply

at once that the non-opposability of man’s great toe is correlated

with the specialization of the human foot for progression only, as

distinguished from prehension; while, in the ape, whose foot has

retained both the progressive and the prehensile function, the hallux

is naturally opposable in adaptation to the animal’s arboreal habits.

He will then call attention to the undeniable fact that, despite these

adaptational differences, the bones in the foot of a Troglodyte ape

are, bone for bone, the counterparts of the bones in the human foot

and not of those in the human hand. He will readily concede, that,

so far as function and adaptedness go, this simian foot is a “hand,”

but he will not fail to point out that it is, at the same time, a

_heeled_ hand equipped with a calcaneum, a talus, a navicular, a

cuboid, and all other structural elements requisite to ally it to

the human foot and distinguish it from the human hand. In fact, Mr.

McCann’s own photographs of the gorilla skeleton show these features

quite distinctly, though he himself, for some reason or other, fails

to speak of them. It is to be feared, however, that his adversaries

may not take a charitable view of his reticence concerning the simian

heel, but may be inclined to characterize his silence as “discreet,”

all the more so, that he himself has uncomplimentarily credited them

with similar discretions in their treatment of unmanageable facts.

In short, Mr. McCann’s case against homology resembles the Homeric

hero, Achilles, in being vulnerable at the “heel.” At all events, the

homology itself is an undeniable fact, and it is vain to tilt against

this fact in the name of adaptational adjustments like “opposability”

and “non-opposability.” Since, therefore, our author has failed to

prove that this feature is too radical to be classed as an adaptive

modification, our only hope of exempting the human skeleton from the

application of the argument in question is to show that argument itself

is inconsequential.

Mr. McCann’s predicament resembles that of the unlucky disputant, who

having allowed a questionable major to pass unchallenged, strives to

retrieve his mistake by picking flaws in a flawless minor. As Dwight

has well said of the human body, “it differs in degree only from that

of apes and monkeys,” and “if we compare the individual bones with

those of apes we cannot fail to see the correspondence.” (“Thoughts

of a Catholic Anatomist,” p. 149.) In short, there exists no valid

anatomical consideration whatever to justify us in subtracting the

human frame from the extension of the general conclusion deduced from

homology. Whosoever, therefore, sees in the homology of organic forms

conclusive evidence of descent from a common ancestor, cannot, without

grave inconsistency, reject the doctrine of the bestial origin of man.

He may still, it is true, exclude the human mind or soul from the

evolutionary account of origins, but, if homology is, in any sense, a

sound argument for common descent, the evolutionary origin of the human

body is a foregone conclusion, and none of the anatomical “differences

in degree” will avail to spare us the humiliation of sharing with the

ape a common family-tree. It remains for us, then, to reëxamine the

argument critically for the purpose of determining as precisely as

possible its adequacy as a genuine demonstration.

To begin with, it must be frankly acknowledged that here the theory

of transformism is, to all appearances, upon very strong ground. Its

first strategic advantage over the theory of immutability consists in

the fact that, unlike the latter, its attitude towards the problem is

positive and not negative. When challenged to explain the structural

uniformities observed in organic Nature, the theory of immutability is

mute, because it knows of no second causes or natural agencies adequate

to account for the facts. It can only account for homology by ascribing

the phenomenon exclusively to the unity of the First Cause, and, while

this may, of course, be the true and sole explanation, to assume it

is tantamount to removing the problem altogether from the province of

natural science. Hence it is not to be wondered at that scientists

prefer the theory of transformism, which by assigning intermediate

causes between the First Cause and the ultimate effects, vindicates

the problem of organic origins for natural science, in assuming the

phenomena to be proximately explicable by means of natural agencies.

Asked whether he believes that God created the now exclusively arboreal

Sloth (_Bradypus_) in a tree, the most uncompromising defender of

fixism will hesitate to reply in the affirmative. Yet, in this case,

what is nowadays, at least, an inherited preadaptation, dedicates the

animal irrevocably to tree-life, and makes its survival upon the ground

impossible.

Analogous preadaptations occur in conjunction with the phenomena of

parasitism, symbiosis and commensalism, all of which offer instances

of otherwise disparate and unrelated organisms that are inseparably

bound together, in some apparently capricious and fortuitous respect,

by a preadaptation of the one to the other. Parasites, guests, or

symbiotes, as the case may be, they are now indissolubly wedded to

some determinate species of host by reason of an appropriate and

congenital adjustment. For all that, however, the association seems

to be a contingent one, and it appears incredible that the associates

were always united, as at present, by bonds of reciprocal advantage,

mutual dependence, or one-sided exploitation. Yet the basis of the

relationship is in each case a now inherited adaptation, which, if it

does not represent the primitive condition of the race, must at some

time have been acquired. For phenomena such as these, orthogenesis,

which makes an organ the exclusive product of internal factors,

conceiving it as a preformed mechanism that subsequently selects a

suitable function, has no satisfactory explanation. Lamarckism, which

asserts the priority of function and makes the environment mold the

organ, is equally inacceptable, in that it flouts experience and

ignores the now demonstrated existence of internal hereditary factors.

But, if between these two extremes some evolutionary _via media_ could

be found, one must confess that it would offer the only conceivable

“natural explanation” of preadaptation.[6] All this, of course, is pure

speculation, but it serves to show that here, at any rate, the theory

of Transformism occupies a position from which it cannot easily be

dislodged.

[6] Vernon Kellogg has expressed this same view in a recent

article, though he frankly admits that it is an as yet

unrealized desideratum. “Altogether,” he says, “it must be

fairly confessed that evolutionists would welcome the discovery

of the actual possibility and the mechanism of transferring

into the heredity of organisms such adaptive changes as can

be acquired by individuals in their lifetime. It would give

them an explanation of evolution, especially of adaptation,

much more satisfactory than any other explanation at present

claiming the acceptance of biologists.” (_Atlantic Monthly_,

April, 1924, p. 488.)

But, besides the advantage of being able to offer a “natural

explanation” of the association of homology with adaptation,

Transformism enjoys the additional advantage of being able to make

the imagination its partisan by means of a visual appeal. Such an

appeal is always more potent than that of pure logic stripped of

sensuous imagery. When it comes to vividness and persuasiveness, the

syllogism is no match for the object-lesson. Retinal impressions have

a hypnotic influence that is not readily exorcised by considerations

of an abstract order—“_Segnius irritant demissa per aurem, Quam quae

sunt oculis subjecta fidelibus_,” says Horace, in the “Ars Poetica.”

Philosophers may distinguish between the magnetic appeal of a graphic

presentation and the logical cogency of the doctrine so presented,

but there is no denying that, in practice, imagination is often

mistaken for reason and persuasion for conviction. Be that as it may,

the ordinary method of bringing home to the student the evolutionary

significance of homology is certainly one that utilizes to the full all

the advantages of visual presentation. Given a class of impressionable

premedics and coeds; given an instructor’s table with skeletons of a

man, a flamingo, an ape and a dog hierarchically arranged thereon;

given an instructor sufficiently versed in comparative osteology to

direct attention to the points in which the skeletons concur: and there

can be no doubt whatever as to the psychological result. The student

forms spontaneously the notion of a common vertebrate type, and the

instructor assures him that this “general type” is not, as it would

be with respect to other subject matter, a mere universal idea with

no formal existence outside the mind, but rather a venerable family

likeness, posed for originally by a single pair of ancestors (or

could it possibly have been, by one self-fertilizing hermaphrodite?)

and recopied from generation to generation, with certain variations

on the original theme, by the hand of an artist called Heredity.

This explanation may be true, but logically consequential it is not.

However, if the dialectic is poor, the pedagogy is beyond reproach,

and the solution proposed has in its favor the fact that it accords

well with the student’s limited experience. He is aware of the

truism that children resemble their parents. Why look for more

recondite explanations when one so obvious is at hand? The atavistic

theory gratifies his instinct for simplification, and, if he be of a

mechanistic turn of mind, the alternative conception of creationism

is quite intolerable. Nevertheless, it goes without saying that

the “inference” of common descent from the data of homology is not

a ratiocination at all, it is only a simple apprehension, a mere

abstraction of similarity from similars—“_Unde quaecumque inveniuntur

convenire in aliqua intentione intellecta_,” says Aquinas, “_voluerunt

quod convenirent in una re_.” (_In lib. II sent._, _dist._ 17, _q.

I_, _a._ 1) Philosophy tells us that the oneness of the universal is

conceptual and not at all extramental or real, but the transformist

insists that the universal types of Zoölogy and Botany are endowed with

real as well as logical unity, that real unity being the unity of the

common ancestor.

Certainly, from the standpoint of practical effectiveness, the

evolutionary argument leaves little to be desired. The presentation is

graphic and the solution simple. But for the critic, to whom logical

sequence is of more moment than psychological appeal, this is not

enough. To withstand the gnawing tooth of Time and the remorseless

probing of corrosive human reason, theories must rest on something

sounder than a mirage of visual imagery!

Tell me where is fancy bred,

Or in the heart or in the head?

How begot, how nourished?

Reply, reply.

It is engendered in the eyes,

With gazing fed; and fancy dies

In the cradle where it lies.

But is it fair thus to characterize the “common ancestors” of

Transformism as figments which, like all other abstractions, have no

extramental existence apart from the concrete objects whence they

were conceived? To be sure, their claim to be real entities cannot be

substantiated by direct observation or experiment, and so a factual

proof is out of the question. Man, the late-comer, not having been

present at the birth of organic forms, can give no reliable testimony

regarding their parentage. In like manner, no _a priori_ proof from the

process of inheritance is available, because heredity, as revealed to

us by the experimental science of Genetics, can account for specific

resemblances only, and cannot be invoked, at present, as an empirically

tested explanation for generic, ordinal, or phyletic resemblances. It

has still to be demonstrated experimentally that the hereditary process

is transcendental to limits imposed by specific differentiation.

There remains, however, the _a posteriori_ argument, which interprets

homology and adaptation as univocal effects ascribable to no other

agency than the dual process of inheritance and variation. What are we

to think of this argument? Does it generate certainty in the mind, or

merely probability?

A moment’s reflection will bring to light the preliminary flaw of

incomplete enumeration of possibilities. To suppose that inheritance

alone can account for structural resemblance is an unwarranted

assumption. Without a doubt, there are other similifying influences at

work in Nature besides inheritance. True, inheritance is one possible

explanation of the similarity of organisms, but it is not the _only_

one. Even among the chemical elements of inorganic nature we find

analogous uniformities or “family traits,” which, in the absence of

any reproductive process whatever, we cannot possibly attribute to

inheritance. Mendeléeff’s discovery of the periodicity of the elements,

arranged in the order of their atomic weights, is well-known. At

each interval of an octave, a succession of chemical types, similar

to those of the preceding octave, recur. Hence elements appearing in

the same vertical column of the Periodic Table have many properties

in common and exhibit what may be called a family resemblance. Now,

we have in the process of atomic disintegration, as observed in

radioactive elements and interpreted by the electronic theory of atomic

structure, a reasonably satisfactory basis upon which to account for

the existence of these inorganic uniformities. Here analogous chemical

constitution, produced in accordance with a general law, results in

uniformity that implies a similar, rather than an identical, cause. The

hypothesis of parallelistic derivation from similar independent origins

accounts quite as well for the observed uniformities as does the

hypothesis of divergent derivation from a single common origin. Why,

then, should we lean so heavily on the already overtaxed principle of

inheritance, when parallelism is as much a possibility in the organic

world as it is an actuality in the inorganic world?

As to the contrast here drawn between inheritance and other similifying

factors, it is hardly necessary to remark that we are speaking of

inheritance as defined in terms of Mendelian experiment and cytological

observation. In the so-called chemical theory of inheritance, the

distinction would be meaningless and the contrast would not exist.

Ehrlich’s disciple, Adami, sets aside all self-propagating germinal

determinants, like the chromomeres, in favor of a hypothetical

“biophoric molecule,” which is to be conceived as a benzine-like

ring bristling with sidechains. Around this determining core the

future organism is built up in definite specificity, as an arch is

constructed about a template. Adami has merely applied Paul Ehrlich’s

ideas concerning metabolism and immunity to the question of heredity,

commandeering for this purpose the latter’s entire toolkit of

receptors, haptophores, amboceptors, etc., as though this grotesque

paraphernalia of crude and clumsy mechanical symbols (which look

for all the world like the wrenches of a machinist, or the lifters

used by the cook to remove hot lids from the kitchen range) could

throw any valuable light whatsoever on the exceedingly complex, and

manifestly vital, phenomenon of inheritance. It does not even deserve

to be called a chemical theory, for, as Starling correctly remarks

concerning Ehrlich’s conception, “though chemical in form,” it is not

so in reality, because “it does not explain the phenomenon by reference

to the known laws of chemistry.” (Cf. _Physiology_, ed. of 1920,

p. 1084.) In a word, the theory of heredity, which seeks to strip

inheritance of its uniqueness as a vital process by identifying it with

the more general physicochemical processes occurring in the organism,

is a groundless speculation, that, far from explaining, flouts the very

observational data which it pretends to elucidate. _Kurz und gut!_

to requite the mechanist, Schäfer, with his own Danielesque phrase,

here, as elsewhere, the mechanists have succeeded in extracting from

the facts, not what the facts themselves proclaim, but what preëxisted

in their own highly-cultured imaginations so well-stocked with cogs,

cranks, ball bearings, and other æsthetic imagery emanating from

polytechnic schools and factories.

But in arguing from the existence of parallelism in the inorganic

world to its possibility in the organic world, we are less liable

to displease the mechanists than those other extremists, the

neo-vitalists, who will be prone to deny all parity between living, and

inanimate, matter. Fortunately, we are in a position to appease the

scruples of the latter by referring to the facts of _convergence_ as

universally accepted evidence that the phenomenon of parallelism occurs

in animate, no less than inanimate, nature. Admitting, therefore, that

the laws of organic morphology are of a higher order than those which

regulate atomic, molecular, and multimolecular structure, these facts

attest, nevertheless, that parallelisms arise in organisms of separate

ancestry which are due, not to heredity, but to the uniform action

of universal morphogenetic forces. Hence general laws can be invoked

to account for organic uniformities with the same right that they

are invoked to account for resemblances existing between the various

members of a chemical “family” like the Halogens. And why should this

not be so? Organisms have much in common that transcends any possible

scheme of evolution and that cannot be brought into alignment with the

position arbitrarily assigned them in the evolutionary family-tree.

They all originate as single cells. Their common means of growth and

reproduction is mitotic cell division. This leads to the production

of a _somatella_, among the protista, and of a _soma_ differentiated

by histogenesis into two or three primary tissues, among the metista.

All these fundamental processes are strikingly uniform throughout

the entire plant and animal world. In these universal properties of

living matter, therefore, we have a common basis for general structural

and organizational laws, which, though irreducible to the “common

ancestors” of Transformism, is quite adequate to account for both the

homologies and analogies of living matter. Accept this basis of general

laws regulating the development of living matter, and there is no

difficulty in seeing why the problems posed by exposure to analogous

environmental conditions are solved in parallel fashion by organisms,

irrespective of whether they are nearly, or distantly, related in the

sense of morphology. Transformism, on the other hand, can only account

for homology at the expense of convergence, and for convergence at the

expense of homology. So far as a common ancestral basis is concerned,

the two kinds of resemblance are, from the very nature of the case,

irreducible phenomena.

It is only, in fact, by surrendering the principle that similarity

entails community of origin, and by falling back on the suggested

common basis of general laws, that Transformism makes room in its

system for the troublesome facts of convergence. “It might be

reiterated in passing,” says Dwight, “that this ‘convergence’ business

is a very ticklish one. We have been taught almost word for word

that resemblance implies relationship, or almost predicates it; but

according to this doctrine it has nothing to do with it whatever.”

(“Thoughts of a Cath. Anat.,” p. 190.) And in a subsequent chapter

he says: “No very deep knowledge of comparative anatomy is needed

for us to know that very similar adaptations for particular purposes

are found in very diverse animals. The curious low grade mammal,

the _Ornithorhynchus_, with a hairy coat and the bill of a duck, is

a familiar instance. We all know that the whales have the general

form of the fish, although they are mammals, and going more into

details we know that the whale’s flipper is on the same general plan

as that of the ancient saurians.... The origin of the eye, according

to evolutionary doctrines, has been a very difficult problem, which

gets worse rather than better the more you do for it. Even if we could

persuade ourselves that certain cells blundered along by the lucky

mating of individuals in whom they were a bit better developed than in

the others till they came to form a most complicated organ of sight, it

would be a sufficient tax on our credulity to believe that this could

come off successfully in some extraordinary lucky species; but that it

should have turned out so well with all kinds of vertebrates is really

too much to ask us to swallow. But this is not all: eyes are very

widely spread among different classes of invertebrates. More wonderful

still, the eyes of certain molluscs and crustacea are on stalks, and

this is found also in various and very different families of fishes.

How did this happen? Was it by way of descent from the molluscs or the

crustacea? If not, how could chance have brought about such a similar

result in diverse forms?” (_Op. cit._, pp. 233-236.)

It may be objected that the resemblances of convergence are superficial

analogies, not to be confounded with fundamental homologies. This

contention may be disputed; for, as we shall see in the next chapter,

there are cases where the convergence is admittedly radical, and

not merely superficial. The distinction, moreover, between shallow

and basic characters is somewhat arbitrary, and its validity is

often questionable. When the skeletal homology that relates the

amphibia to the mammals, for instance, is traced to the root of the

vertebrate family tree, we find it all but disappearing in a primitive

Amphioxus-like chordate, whose so-called skeleton contains no trace of

bone or cartilage. Hence, if we go back far enough, the homologies of

today become the convergences of a geological yesterday, and we find

the vertebrate type of skeleton arising independently in reptiles,

mammals, amphibia, and fishes.

Again, there are times when convergent analogies appear to be more

representative of the common racial heritage than the underlying

structure itself, tempting the evolutionist to fly in the face of

the orthodox interpretation, which rigidly rules out analogy in

favor of homology, and refuses to accept the eloquent testimony

of a remarkable resemblance merely because of a slight technical

discrepancy in the structural substrate. A large pinching claw, or

chela, for example, occurs in two organisms belonging to the phylum

of the arthropods, namely, the lobster and the African scorpion. Both

chelæ are practically identical in structure, but, unfortunately, the

chela of the lobster arises from a different appendage than that from

which the scorpion’s chela emerges. If they arose from corresponding

appendages, they would be pronounced “homologous organs” and acclaimed,

without hesitation, as strong evidence in favor of the common origin

of all the arthropods. In proof of this, we call attention to the

importance attached to the adaptations affecting homologous bones in

fossil “horses.” As it is, however, the two chelæ are analogous, and

not homologous, organs. Hence, technically speaking, the two chelæ are

utterly unrelated structures. To the eye of common sense, however, the

likeness appears to be far more important than the difference, and the

average person will be inclined to view the resemblance as evidence of

a community of type. In fact, the tendency to discard superficial, and

to retain only fundamental, uniformities, is dangerous to the theory of

Transformism. When we confine our attention to what is really basic, we

find that the resemblances become so generalized and widespread that

specific conclusions as to descent become impossible, and we lose all

sense of direction in a clueless labyrinth of innumerable, yet mutually

contradictory, possibilities.

Finally, it may be noted in passing that, though it is customary

with evolutionists to regard homologous characters as the tenaciously

persistent heritage of primeval days, and to look upon adaptational

characters as adventitious and accessory to the aforesaid primitive

heritage, the supposedly older and more fundamental characters fail to

give, by the manifestation of greater fixity, any empirical evidence

whatever of their being more deeply or firmly rooted in the hereditary

process than the presumably newer adaptational characters. We have,

therefore, no experimental warrant for appropriating homologous,

rather than adaptational, characters to the process of inheritance.

“It is sometimes asserted,” says Goodrich, “that old-established

characters are inherited, and that newly begotten ones are not, or are

less constant, in their reappearance. This statement will not bear

critical examination. For, on the one hand, it has been conclusively

shown by experimental breeding that the newest characters may be

inherited as constantly as the most ancient.... While, on the other

hand, few characters in plants can be older than the green color

due to chlorophyll, yet it is sufficient to cut off the light from

a germinating seed for the greenness to fail to appear. Again, ever

since Devonian times vertebrates have inherited paired eyes; yet,

as Professor Stockard has shown, if a little magnesium chloride is

added to the sea water in which the eggs of the fish _Fundulus_ are

developing, they will give rise to embryos with one median cyclopean

eye! Nor is the suggestion any happier that the, so to speak, more

deep-seated and fundamental characters are more constantly inherited

than the trivial or superficial. A glance at the organisms around

us, or the slightest experimental trial, soon convinces us that the

apparently least important character may reappear as constantly as

the most fundamental. But while an organism may live without some

trivial character, it can rarely do so when a fundamental character is

absent, hence such incomplete individuals are seldom met in Nature.”

(_Science_, Dec. 2, 1921, p. 530.)

But, whether it be upon, or beneath, the surface, similitude of _any

kind_ suffices to establish our contention that inheritance is not the

only similifying influence present in organisms, and that resemblance

is perfectly compatible with independence of ancestry. We have,

therefore, an alternative for inheritance in the explanation of organic

uniformities, and by the admission of this alternative, which, for the

rest, is factually attested by the universally acknowledged phenomena

of convergence, the inference of common descent from structural

resemblance is shorn of the last remnant of its demonstrative force, as

an _a posteriori_ argument.

But a still more serious objection to the evolutionary interpretation

of homology and preadaptation arises from its intrinsic _incoherency_.

Evolution, as previously stated, is assumed to be the resultant of

a twofold process, namely, _inheritance_ and _variation_. The first

is a conservative and similifying process, which transmits. The

second is a progressive and diversifying process, which diverts.

To the former process are due the uniformities of homology, to

the latter the deviations of adaptation. Upon the admission of

evolutionists themselves, however, neither of these processes behaves

in a manner consistent with its general nature, and both of them

are flagrantly unfaithful to the principal rôles assigned to them.

Nowadays the hereditary process transmits _adaptational_, as well

as _homologous_, characters. If, then, adaptational characters are

more recent than homologous characters, there must have been a time

when inheritance ceased to _similify_ and become a _diversifying_

process by transmitting what it did not receive from the previous

generation. There were times when, not content with simply reiterating

the past, it began to divert former tendencies into novel channels.

In other words, inheritance becomes dualized into a paradoxical

process, which both perpetuates the old and appropriates the new.

The same inconsistency is manifest in the process of variation,

which capriciously produces _convergent_, no less than _divergent_,

adaptations. In two fundamentally identical structures, like the wing

of a bird and the foreleg of a cat, variation is said to have produced

diverse adaptations. In two fundamentally diverse structures, like

the head of an octopus and the head of a frog, variation is said to

have produced an identical adaptation, namely, the vertebrate type of

eye. It appears, therefore, that the essentially diversifying process

of variation can become, on occasion, a simplifying process, which,

instead of solving environmental problems in an original manner,

prefers to employ uniform and standardized solutions, and to cling to

its old stereotyped methods. Inheritance similifies and diversifies,

variation converges and diverges. It is futile to attempt to reduce

either of these protean processes to a condition that even approximates

consistency. The evolutionist blows hot and cold with the same breath.

Verily, his god is Proteus, or the double-headed Janus!

_Summa summarum_: The evolutionary argument from homology is defective

in three important respects: (1) in its lack of experimental

confirmation; (2) in its incomplete enumeration of the disjunctive

possibilities; (3) in its inability to construct a scheme of

transmutation that synthesizes inheritance and variation in a logically

coherent, and factually substantiated formula. The first two defects

are not necessarily fatal to the argument as such. Though they destroy

its pretensions to conclusiveness, they do not preclude the fulfilment

of the moderate claim made in its behalf by Prof. T. H. Morgan, who

says: “In this sense (_i.e._, as previously stated) the argument from

comparative anatomy, while not a demonstration, carries with it, I

think, a high degree of probability.” (“A Critique of the Theory of

Evolution,” p. 14.) The third defect is more serious. The apparently

irreducible antagonism which the evolutionary assumption introduces

between inheritance and variation has been sensed even by the adherents

of transformism themselves, and they have searched in vain for a

formula, which, without sacrificing the facts, would bring into concord

the respective rôles of these discordant factors. “It follows,” says

Osborn, “as an unprejudiced conclusion from our present evidence that

upon Weismann’s principle we can explain inheritance but not evolution,

while with Lamarck’s principle and Darwin’s selection principle we

can explain evolution, but not, at present, inheritance. Disprove

Lamarck’s principle and we must assume that there is some third factor

in evolution of which we are ignorant.” (_Popular Science Monthly_,

Jan., 1905.) The point is well taken, and unless, as Osborn suggests,

there is a _tertium quid_ by means of which the discord can be resolved

into ultimate harmony, we see no way of liberating the theory of

Transmutation from this embarrassing dilemma.

CHAPTER III

FOSSIL PEDIGREES

“_By dint of such great efforts we succeeded only in piecing

together genial romances more or less historical._”—B. Grassi,

Prof. of Comparative Anatomy, Univ. of Rome, “La vita” (1906),

p. 227.

§ 1. =The Argument in the Abstract=

The palæontological argument for evolution is based upon the observed

gradual approximation in type of the earlier forms of life, as

represented by the fossils still preserved in successive geological

strata, to the later forms of life, as represented by the contemporary

species constituting our present flora and fauna. Here the observed

distribution in time supplements and confirms the argument drawn from

mere structural affinity. Here we are no longer dealing with the

spatial gradation of contemporary forms, arranged on a basis of greater

or lesser similarity (the gradation whence the zoölogist derives his

argument for evolution), but with a temporal gradation, which is

simultaneously a morphological series and an historical record. The

lower sedimentary rocks contain specimens of organic life very unlike

modern species, but, the higher we ascend in the geological strata,

the more closely do the fossil forms resemble our present organisms.

In fact, the closeness of resemblance is directly proportional to the

proximity in time, and this seems to create a presumption that the

later forms of life are the modified descendants of the earlier forms.

Considered in the abstract, at least, such an argument is obviously

more formidable than the purely anatomical argument based on the

degrees of structural affinity observable in contemporary forms. It

ought, therefore, to be extremely persuasive, provided, of course,

it proceeds in rigorous accord with indubitably established facts and

rules out relentlessly the alloy of uncritical assumptions.

Here, likewise, we find the theory of transformism asserting its

superiority over the theory of immutability, on the ground that

evolutionism can furnish a natural explanation for the gradational

distribution of fossil types in the geological strata, whereas the

theory of permanence resorts, it is said, to a supernaturalism

of reiterated “new creations” alternating with “catastrophic

exterminations.” Now, if this claim is valid, and it can be shown

conclusively that fixism is inevitably committed to a postulate of

superfluously numerous “creations,” then the latter theory is shorn

of all right to consideration by Occam’s Razor: _Entia non sunt

multiplicanda sine ratione._ It is rather difficult to conceive of the

Creator as continually blotting out, and rewriting, the history of

creation, as ruthlessly exterminating the organisms of one age, only

to repopulate the earth subsequently with species differing but little

from their extinct predecessors—_ad quid perditio haec_? Such procedure

hardly comports with the continuity, regularity and irrevisable

perfection to be expected in the works of that Divine Wisdom, which

“reacheth ... from end to end mightily and disposeth all things

sweetly” (_Wisdom_, viii; 1), which “ordereth all things in measure,

and number and weight.” (_Wis._ xi; 21.)

Following the lead of other evolutionists, Wasmann has striven to

saddle fixism with the fatuity of periodic catastrophism and “creation

on the installment plan.” But even Cuvier, who is credited with

having originated the theory of catastrophism, did not go to the

absurd extreme of hypothecating reiterated creations, but sought

to explain the repopulation of the earth after each catastrophe

by means of migrations from distant regions unaffected by the

catastrophe. Historically, too, fixism has had its uniformitarian, as

well as its catastrophic, versions. In fact, Huxley classifies both

uniformitarianism and catastrophism as fixistic systems, when he

says: “I find three more or less contradictory systems of geologic

thought ... standing side by side in Britain. I shall call one of them

Catastrophism, another Uniformitarianism, the third Evolutionism.”

(“Lay Sermons,” p. 229.) Obviously, then, fixism is separable from

the hypothesis of repeated catastrophes alternating with repeated

“creations.” Stated in proper terms, it is at one with evolutionism

in rejecting as undemonstrated and improbable the postulate of

reiterated cataclysms. It freely acknowledges that, in the absence

of positive evidence of their occurrence, the presumption is against

extraordinary events, like wholesale catastrophes. It sanctions

the uniformitarian tenet that ordinary cosmic processes are to be

preferred to exceptional ones as a basis of geological explanation,

and it repudiates as unscientific any recourse to the unusual or

the miraculous in accounting for natural phenomena. Its sole point

of disagreement with evolutionism is its refusal to admit organic

changes of _specific_ magnitude. It does, however, admit germinal

changes of _varietal_ magnitude. It also recognizes that the external

characters of the phenotype are the joint product of germinal factors

and environmental stimuli, and admits, in consequence, the possibility

of purely _somatic changes_ of considerable profundity being induced

by widespread and persistent alterations in environmental conditions.

Like Darwin, the uniformitarian fixist ascribes the origination of

organic life to a single vivifying act on the part of the Creator, an

act, however, that was _formative_ rather than _creative_, because the

primal forms of life, whether few or many, were all evolved through

Divine influence from preëxistent inorganic matter. Unlike Darwin, he

ascribes the continuation of organic life to generative processes that

were univocal (_generationes univocae_), and not gradually-equivocal

(_generationes paulatim aequivocae_). In the next chapter, we shall see

that, in attributing the initial formation of species to a Divine act,

neither Darwin nor the creationists exposed themselves to the charge of

explaining the “natural” by means of the “miraculous.” And, as for the

process by which living forms were continued upon earth, the univocal

reproductive process upheld by fixism is more manifestly a natural

process than the gradually-equivocal generation of variable inheritance

hypothecated by the theory of transmutation. The sole matter of dispute

between the two views is whether the life-cycles of organisms are

circles or spirals.

But all this, it will be said, is purely negative. Merely to refrain

from any recourse to the extraordinary or the supernatural is by no

means sufficient. “Natural explanations” must be explanatory as well

as natural. Unless there be a simplification, a reduction of plurality

to unity, a resolution of many particular problems into a common

general problem, we have no explanation worthy of the name. Granting,

therefore, that uniformitarian fixism does not recur to the anomalous

or the miraculous, it still lies open to the charge of failing in its

function as an explanation, because it multiplies origins in both space

and time. Transformism, on the contrary, is said to elucidate matters,

inasmuch as it unifies origins spatially and temporally.

That transformism successfully plausibleizes a unification of origins

in space, is true only in a limited and relative sense. The most

that can be said for the assumption, that resemblances rest on the

principle of common inheritance, is that it permits of a numerical

reduction of origins, but this numerical reduction will, by an

intrinsic necessity, always fall short of absolute unification. The

monophyletic derivation of all organic forms from one primordial cell

or protoblast is a fantastic dream, for which, from the very nature

of things, natural science does not, and can not, furnish even the

semblance of an objective basis. The ground is cut from under our feet,

the moment we attempt to extend the principle of descent outside the

limits of an organic phylum. The sole basis of inference is a group

of uniformities, and, unless these uniformities predominate over the

diversities, there can be no rational application of the principle of

transformism. Hence, the hypothesis, that organisms are consanguineous

notwithstanding their differences, loses all value as a solution

at the point where resemblances are outweighed by diversities. The

transmutation assumed to have taken place must be never so complete as

to have obliterated all recognizable vestiges of the common ancestral

type. “Whenever,” says Driesch, “the theory that, in spite of their

diversities, the organisms are related by blood, is to be really useful

for explanation, it must necessarily be assumed in every case that

the steps of change, which have led the specific form A to become the

specific form B, have been such as only to change in part that original

form A. That is to say: the similarities between A and B must never be

overshadowed by their diversities.” (“Science and Philosophy of the

Organism,” v. I, p. 254.) When, therefore, the reverse is true and

diversities are prevalent over uniformities, we are left without clue

or compass in the midst of a labyrinth of innumerable possibilities.

Such are the limits imposed by the very nature of the evidence itself,

and the scientists, who transgress these limits, by attempting to

correlate the primary phyla, are on a par with those unconvincible

geniuses, who continually besiege the Patent Office with schemes ever

new and weird for realizing the chimera of “perpetual motion.”

Thus scientific transformism is unable to simplify the problem beyond a

certain irreducible plurality of forms, lesser only in degree than the

plurality postulated by fixism. This being the case, the attempts of

Wasmann and Dorlodot to prune the works of Creation with Occam’s Razor

are not only presumptuous, but precarious as well. _Qui nimis probat,

nihil probat!_ If it be unworthy of God to multiply organic origins

in space, then monophyletic descent is the only possible alternative,

and polyphyletic transformism falls under the same condemnation as

fixism. Yet the polyphyletic theory of descent is that to which both

Wasmann and Dorlodot subscribe, as it is, likewise, the only kind of

transformism which science can ever hope to plausibleize. Besides, too

close a shave with Occam’s Razor would eliminate creation altogether,

since all theologians cheerfully admit that it was the result of a free

and unnecessary act on the part of God. When we apply our _rationes

convenientiae_ to the Divine operations, we must not make the mistake

of applying them to the Divine action itself instead of the created

effects of that action. We may be competent to discern disorder and

irregularity in finite things, but we are wholly incompetent to

prescribe rules for Divine conduct. To say that God is constrained

by His infinite Wisdom to indirect, rather than direct, production,

or that He must evolve a variety of forms out of living, rather than

non-living, matter, is to be guilty of ridiculous anthropomorphism.

There is no _a priori_ reason, founded upon the Divine attributes,

which restricts God’s creative action to the production of this, or

that, number of primordial organisms, or which obliges him to endow

primitive organisms with the power of transmutation.

But the fact that these _rationes convenientiae_ fail to establish

the _a priori_ necessity of a unification of organic origins in

space, does not imply that they are without value in suggesting the

unification of organic origins in time. Order and regularity are not

excluded by spatial multiplicity, but they may easily be excluded by

the incongruities of an irregular succession of events. Indeterminism

and chance are, indeed, inseparable from the course of Nature. There is

in matter an unlimited potentiality, incommensurate with the limited

efficacy of natural agencies. Hence it evades the absolute control of

all finite factors and forces. But the anomalies and irregularities,

which are contingent upon the limitation or frustration of second

causes unable to impose an iron necessity upon evasive matter, are

not referable to the First Cause, but rather to the finite efficacy

of second causes. Such anomalies in natural processes, consequently,

are not inconsistent with infinite wisdom and power on the part of

the Creator. If, on the contrary, the anomaly occurs, not in the form

of an accidental frustration of a natural agency, but in the form

of an intrusive “new creation,” the irregularity in question would

then be referable to the Creator Himself, and such derogations of

order are inadmissible, except as manifestations of the supernatural.

In fact, the abrupt and capricious insertion of a “new creation”

into an order already constituted, say, for instance, the sudden

introduction of Angiosperms in the Comanchian period, or of mammals in

the Tertiary, would be out of harmony with both reason and revelation.

Unless there is a positive reason for supposing the contrary, we must

presume that, subsequent to the primordial constitution of things,

the Divine influence upon the world has been concurrent rather than

revolutionizing. Hence a theory of origins, compatible with the

simultaneous “creation” of primal organisms, is decidedly preferable

to a theory, which involves successive “creations” at random. That

transformism dispenses with the need of assuming a succession of

“creative” acts, is perfectly obvious, and, unless fixism can emulate

its rival system in this respect, it cannot expect to receive serious

attention.

But once fixism assumes the simultaneousness of organic origins,

it encounters, in the absence of modern organic types from ancient

geological strata, a new and formidable difficulty. Cuvier’s theory

of numerous catastrophes followed by wholesale migrations of the

forms, which had escaped extinction, is tantamount to an appeal to the

extraordinary and the improbable for purposes of explanation, and this,

as we have seen, is an expedient, which natural science is justified

in refusing to sanction. Nor does the appeal to the incompleteness of

the geological record offer a more satisfactory solution. It is tax

enough, as we shall see, upon our credulity, when the transformist

seeks to account thereby for the absence of intermediate types, but

to account in this fashion for the absence of palæozoic Angiosperms

and mammals is asking us to believe the all-but-incredible. It would

not, therefore, be advisable for the fixist to appropriate the line of

defense suggested for him by Bateson—“It has been asked how do you

_know_ for instance that there were no mammals in Palæozoic times? May

there not have been mammals somewhere on the earth though no vestige of

them has come down to us? We may feel confident there were no mammals

then, but are we sure? In very ancient rocks most of the great orders

of animals are represented. The absence of the others might by no great

stress of imagination be ascribed to accidental circumstances.” But the

sudden rise of the Angiosperms in the early part of the Mesozoic era is

an instance of _de novo_ origin that is not so easily explained away.

Hence Bateson continues: “Happily, however, there is one example of

which we can be sure. There were no Angiosperms—that is to say ‘higher

plants’ with protected seeds—in the carboniferous epoch. Of that age we

have abundant remains of a worldwide and rich flora. The Angiosperms

are cosmopolitan. By their means of dispersal they must immediately

have become so. Their remains are very readily preserved. If they

had been in existence on the earth in carboniferous times they must

have been present with the carboniferous plants, and must have been

preserved with them. Hence we may be sure that they did appear on earth

since those times. We are not certain, using certain in the strict

sense, that Angiosperms are the lineal descendants of the carboniferous

plants, but it is much easier to believe that they are than that they

are not.” (_Science_, Jan. 20, 1922, p. 58.)

It would thus appear, that not all the organic types of either the

plant, or the animal, kingdom are of equal antiquity, and that the

belated rise of unprecedented forms has the status of an approximate

certainty, wherewith every theory of origins must inevitably reckon.

How, then, is the fixist to reconcile this successive appearance of

organisms with the simultaneous “creation” advocated by St. Augustine

and St. Thomas of Aquin? Unless there be some other gradual process

besides transmutation, to bridge the interval between the creative

fiat and the eventual appearance of modern types, there seems to be no

escape from the dilemma.

This brings us to St. Augustine’s theory of the evolution of organic

life from inorganic matter, which Dorlodot sophistically construes

as supporting the theory of descent. According to St. Augustine, for

whose view the Angelic Doctor expressed a deliberate preference, the

creation of the corporeal world was the result of a single creative

act, having an immediate effect in the case of minerals, and a remote

or postponed effect in the case of plants and animals (cf. “De Genesi

ad litteram,” lib. V, c. 5). Living beings, therefore, were created,

not in actuality, but in germ. God imparted to the elements the

power of producing the various plants and animals in their proper

time and place. Hence living beings were created causally rather

than formally, by the establishment of causal mechanisms or natural

agencies especially ordained to bring about the initial formation of

the ancestral forms of life. The Divine act initiating these “natural

processes” (_rationes seminales, rationes causales_) in inorganic, and

not in living, matter, was instantaneous, but the processes, which

terminated in the formation of plants and animals, in their appointed

time and place, were in themselves gradual and successive. Thus by an

influx of Divine power the earth was made pregnant with the promise

of every form of life—“_Sicut matres gravidae sunt foetibus, sic ipse

mundus est gravidus causis nascentium._” (Augustine, lib. III, “de

Trinitate,” c. 9.)

By reason of this doctrine, the Louvain professor claims that

St. Augustine was an evolutionist, and so, indeed, he was, if by

evolution is meant a gradual production of organisms from inorganic

matter. But if, on the contrary, by evolution is meant a progressive

differentiation and multiplication of organic species by transmutation

of preëxistent forms of life, or, in other words, if evolution is taken

in its usual sense as synonym for transformism, then nothing could

be more absurdly anachronistic than to ascribe the doctrine to St.

Augustine. The subject of the gradual process postulated by the latter

was, not living, but _inorganic_, matter, and the process was conceived

as leading to the _formation_, and not the transformation, of species.

The idea of variable inheritance did not occur to St. Augustine, and he

conceived organisms, once they were in existence, as being propagated

exclusively by univocal reproduction (_generatio univoca_). It is the

fixist, therefore, rather than the transformist, who is entitled to

exploit the Augustinian hypothesis. In fact, it is only the vicious

ambiguity and unlimited elasticity of the term evolution, which avail

to extenuate the astounding confusion of ideas and total lack of

historic sense, that can bracket together under a common term the

ideology of Darwin and the view of St. Augustine.

§ 2. The Argument in the Concrete

But it is our task to criticize the theory of transformism, and not to

throw a life-line to fixism, by advocating gradual formation of species

as the only feasible alternative to gradual transformation of species.

Perhaps, this particular life-line will not be appreciated any way;

for the fixist may, not without reason, prefer to rest his case on the

contention that the intrinsic _time-value_ of geological formations is

far too problematic for certain conclusions of any sort. In maintaining

this position, he will have the support of some present-day geologists,

and can point, as we shall see, to facts that seem to bear out his

contention. In fact, the cogency of the palæontological argument

appears to be at its maximum in the abstract, and to evaporate the

moment we carry it into the concrete. The lute seems perfect, until we

begin to play thereon, and then we discover certain rifts that mar the

effect. It is to these rifts that our attention must now be turned.

The first and most obvious flaw, in the evolutionary interpretation

of fossil series, is the confounding of succession with filiation.

Thinkers, from time immemorial, have commented on the deep chasm

of distinction, which divides historical from causal sequence, and

philosophers have never ceased to inveigh against the sophistical

snare of: _Post hoc, ergo propter hoc._ That one form of life has

been subsequent in time to another form of life is, in itself, no

proof of descent. “Let us suppose,” says Bather, “all written records

to be swept away, and an attempt made to reconstruct English history

from coins. We could set out our monarchs in true order, and we might

suspect that the throne was hereditary; but if on that assumption

we were to make James I, the son of Elizabeth—well, but that’s

just what palæontologists are constantly doing. The famous diagram

of the Evolution of the Horse which Huxley used in his American

lectures has had to be corrected in the light of the fuller evidence

recently tabulated in a handsome volume by Prof. H. F. Osborn and

his coadjutors. _Palæotherium_, which Huxley regarded as a direct

ancestor of the horse, is now held to be only a collateral, as the

last of the Tudors were collateral ancestors of the Stuarts. The later

_Ancitherium_ must be eliminated from the true line as a side branch—a

Young Pretender. Sometimes an apparent succession is due to immigration

of a distant relative from some other region—‘The glorious House of

Hanover and Protestant Succession.’ It was, you will remember, by such

migrations that Cuvier explained the renewal of life when a previous

fauna had become extinct. He admitted succession but not descent.”

(_Science_, Sept. 17, 1920, p. 261.)

But, if succession does not imply descent, descent, at least, implies

succession, and the fact that succession is the necessary corollary of

descent, may be used as a corrective for the erroneous allocations made

by neontologists on the basis of purely morphological considerations.

The _priority_ of a type is the _sine qua non_ condition of its

being accepted as _ancestral_. It is always embarrassing when, as

sometimes happens, a “descendant” turns out to be older than, or even

coëval with, his “ancestor.” If, however, the historical position of

a form can be made to coincide with its anatomical pretensions to

ancestry, then the inference of descent attains to a degree of logical

respectability that is impossible in the case of purely zoölogical

evidence. Recent years have witnessed a more drastic application of the

historical test to morphological speculations, and the result has been

a wholesale revision of former notions concerning phylogeny. “I could

easily,” says Bather, “occupy the rest of this hour by discussing the

profound changes wrought by this conception on our classification. It

is not that orders and classes hitherto unknown have been discovered,

not that some erroneous allocations have been corrected, but the whole

basis of our system is being shifted. So long as we were dealing with

a horizontal section across the tree of life—that is to say, with

an assemblage of approximately contemporaneous forms—or even with a

number of such horizontal sections, so long were we confined to simple

description. Any attempt to frame a causal connection was bound to be

speculative.” (_Ibidem_, p. 258.) Whether zoölogists will take kindly

to this “shifting of the whole basis” of classification, remains to be

seen. Personally, we think they would be very ill-advised to exchange

the solid observational basis of homology for the scanty facts and

fanciful interpretations of palæontologists.

The second stumbling block in the path of Transformism is the

occurrence of convergence. We have seen that, in the palæontological

argument, descent is inferred conjointly from similarity and

succession, and that, in the abstract, this argument is very

persuasive. One of the concrete phenomena, however, that tend to make

it inconsequential, is the undoubted occurrence of convergence. Prof.

H. Woods of Cambridge, in the Introduction to the 5th edition of his

“Palæontology” (1919), speaks of three kinds of convergence (cf.,

pp. 14, 15, 16), which, as a matter of convenience, we may term the

parallelistic, the radical, and the adaptational, types of convergence.

A brief description of each type will serve to elucidate its nature and

its significance:

(1) Parallelistic convergence implies the appearance of parallel

modifications in the homologous parts of organisms regarded as

diverging from common stock in two distinct collateral lines, that

were independent at the time of the appearance in both of the said

parallel modifications. Speaking of the fossil cœlenterates known as

_Graptolites_, Professor Woods says: “In some genera the hydrothecæ

of different species show great variety of form, those of one species

being often much more like those of a species belonging to another

genus than to other species of the same genus.” (“Palæontology,” 5th

ed., 1919, p. 69.) As another instance of this phenomenon, the case

of the fossil ungulates of South America, spoken of as _Litopterna_,

may be cited, and the case is peculiarly interesting because of its

bearing on that _pièce de résistance_ of palæontological evidence,

the Pedigree of the Horse. “The second family of Litopterna,” says

Wm. B. Scott, “the Proterotheriidæ, were remarkable for their many

deceptive resemblances to horses. Even though those who contend that

the Litopterna should be included in the Perissodactyla should prove to

be in the right, there can be no doubt that the proterotheres were not

closely related to the horses, but formed a most striking illustration

of the independent acquisition of similar characters through parallel

or convergent development. The family was not represented in the

Pleistocene, having died out before that epoch, and the latest known

members of it lived in the upper Pliocene.... Not that this remarkable

character was due to grotesque proportions; on the contrary, they

looked far more like the ordinary ungulates of the northern hemisphere

than did any of their South American contemporaries; it is precisely

this resemblance that is so notable.... The feet were three-toed,

except in one genus (_Thoatherium_) in which they were single-toed, and

nearly or quite the whole weight was carried upon the median digit, the

laterals being mere dew-claws. The shape of the hoofs and the whole

appearance of the foot was surprisingly like those of the three-toed

horses, but there were certain structural differences of such great

importance, in my judgment, as to forbid the reference of these

animals, not merely to the horses, but even to the perissodactyls.” (“A

History of Land Mammals in the Western Hemisphere,” p. 499.)

For this sort of parallelism, the Lamarckian and Darwinian types of

evolution by addition can offer no rational explanation. It could,

perhaps, be accounted for upon the Batesonian hypothesis of evolution

by loss of inhibition, that is to say, the coincident appearance of

convergent characters in collateral lines might be interpreted as

being due to a parallel loss in both lines of the inhibitive genes,

which had suppressed the convergent feature in the primitive or common

stock. We say that the convergence _might_ be so interpreted, because

the interpretation in question would, at best, be merely optional

and not at all necessary; for in the third, or adaptational, type of

convergence, we shall see instances of parallel modifications occurring

in completely independent races, whose morphology and history alike

exclude all possibility of hereditary connection between them. Hence,

even in the present case, nothing constrains us to accept the genetic

interpretation.

(2) Radical convergence, which Woods styles heterogenetic homœomorphy,

is described by him as follows: “Sometimes two groups of individuals

resemble each other so closely that they might be regarded as belonging

to the same genus or even to _the same species_ (italics mine), but

they have descended from different ancestors since they are found to

differ in development (ontogeny) or in their palæontological history;

this phenomenon, of forms belonging to different stocks approaching

one another in character, is known as convergence or heterogenetic

homœomorphy, and may occur at the same geological period or at widely

separated intervals. Thus the form of oyster known as _Gryphaea_ has

originated independently from oysters of the ordinary type in the Lias,

in the Oölites, and again in the Chalk; these forms found at different

horizons closely resemble one another and have usually been regarded as

belonging to one genus (_Gryphaea_), but they have no direct genetic

connection with one another.” (“Palæontology,” 5th ed., 1919, p. 15.)

Comment is almost superfluous. If even _specific_ resemblance is no

proof of common origin, then what right have we to interpret any

resemblance whatever in this sense? With such an admission, the whole

bottom drops out of the evolutionary argument. When the theory of

descent is forced to account for heterogenetic resemblance at expense

of all likelihood and consistency, when it cannot save itself except by

blowing hot and cold with one breath, one is tempted to exclaim: “Oh,

why bother with it!”

(3) Adaptational convergence is the occurrence of parallel

modifications due to analogous specialization in unrelated forms,

whose phylogeny has been obviously diverse. “Also, animals belonging

to quite distinct groups,” says Woods, “may, when living under similar

conditions, come to resemble one another owing to the development of

adaptive modifications, though they do not really approach one another

in essential characters; thus analogous or parallel modifications may

occur in independent groups—such are the resemblances between flying

reptiles (_Ornithosaurs_) and birds, and between sharks, icthyosaurs

and dolphins.” (_Op. cit._, p. 16.) As this type of convergence has

been discussed in a previous article, with reference to the mole and

mole-cricket, it need not detain us further.

All these types of convergence, but especially the second type, are

factual evidence of the compatibility of resemblance with independent

origin, and the fact of their occurrence tends to undermine the

certainty of the phylogenetic inferences based on fossil evidence;

all the more so, that, thanks to its bad state of preservation, and

the impossibility of dissection, even superficial resemblances may

give rise to false interpretations. And, as for the cases of radical

convergence, there is no denying that they strike at the very heart of

the theory of descent.

The third difficulty for Transformism arises from the discontinuity

of the geological record. It was one of the very first discrepancies

to be discovered between evolutionary expectation and the actual

results of research. The earliest explorations revealed a state of

affairs, that subsequent investigations have failed to remedy: on

the one hand, namely, a notable absence of intermediate species to

bridge the gaps between the fossil genera, and on the other hand,

the sudden and simultaneous appearance of numerous new and allied

types unheralded by transitional forms. Since Darwin had stressed the

gradualness of transmutation, the investigators expected to find the

transitional means more numerous than the terminal extremes, and were

surprised to find, in the real record of the past, the exact reverse

of their anticipation. They found that the classes and families of

animals and plants had always been as widely separated and as sharply

differentiated as they are today, and that they had always formed

distinct systems, unconnected by transitional links. The hypothetical

“generalized types,” supposed to combine the features of two or three

families, have never been found, and most probably never will be;

for it is all but certain that they never existed. Occasionally, it

is true, palæontologists have discovered isolated types, which they

interpreted as annectant forms, but a single pier does not make a

bridge, and only too often it chanced that the so-called annectant

type, though satisfactory from the morphological standpoint, was more

recent than the two groups, to which it was supposed to be ancestral.

But it will make matters plainer, if we illustrate what is meant by the

discontinuity or incompleteness of the fossil record, by reference to

some concrete series, such as the so-called Pedigree of the Horse.

Whenever a series of fossils, arranged in the order of their historical

sequence, exhibits a gradation of increasing resemblance to the latest

form, with which the series terminates, such a series is called a

palæontological pedigree, and is said to represent so many stages in

the racial development or phylogeny of the respective modern type. The

classical example of this sort of “pedigree” is that of the Horse.

It is, perhaps, one of the most complete among fossil “genealogies,”

and yet, as has been frequently pointed out, it is, as it stands,

extremely incomplete. Modern representatives of the _Equidae_, namely,

the horse, the ass and the zebra, belong to a common genus, and are

separated from one another by differences which are merely specific,

but the differences which separate the various forms, that compose

the “pedigree of the Horse,” are generic. We have, to borrow Gerard’s

simile, nothing more than the piers of the evolutionary bridge, without

the arches, and we do not know whether there ever were any arches.

There is, indeed, a sort of progression, _e.g._, from the four-toed

to a one-toed type, so that the morphological gradation does, in some

degree, coincide with temporal succession. But, on the other hand, the

fossil forms, interpreted as stages in the phylogeny of the Horse, are

separated from one another by gaps so enormous, that, in the absence

of intermediate species to bridge the intervals, it is practically

impossible, particularly in the light of our experimental knowledge

of Genetics, to conceive of any transition between them. Nor is this

all. The difficulty is increased tenfold, when we attempt to relate the

_Equidae_ to other mammalian groups. Fossil ungulates appear suddenly

and contemporaneously in the Tertiary of North America, South America

and Europe, without any transitional precursors, to connect them with

the hypothetical proto-mammalian stock, and to substantiate their

collaterality with other mammalian stocks.

To all such difficulties the evolutionist replies by alleging the

incompleteness of the geological record, and modern handbooks

on palæontology devote many pages to the task of explaining why

incompleteness of the fossil record is just what we should expect,

especially in the case of terrestrial animals. The reasons which

they assign are convincing, but this particular mode of solving the

difficulty is a rather precarious one. Evolutionists should not

forget that, in sacrificing the substantial completeness of the

record to account for the absence of intermediate species, they are

simultaneously destroying its value as a proof of the relative position

of organic types in time. Yet this, as we have seen, is precisely the

feature of greatest strategic value in the palæontological “evidence”

for evolution. We must have absolute _certainty_ that the reputed

“ancestor” was in existence prior to the appearance of the alleged

“descendant,” or the peculiar force of the palæontological argument

is lost. It would be preposterous for the progeny to be prior to,

or even coëval with, the progenitor, and so we must be quite sure

that what we call “posterity” is really posterior in time. Now the

sole argument that palæontology can adduce for the posteriority of

one organic type as compared with another is the negative evidence

of its non-occurrence, or rather of its non-discovery, in an earlier

geological formation. The lower strata do not, so far as is known,

contain the type in question, and so it is concluded that this

particular form had no earlier history. Such an inference, as is

clear, is not only liable to be upset by later discoveries, but has

the additional disadvantage of implicitly assuming the substantial

completeness of the fossil record, whereas the absence of intermediate

species is only explicable by means of the assumed incompleteness of

the selfsame record. The evolutionist is thus placed in the dilemma

of choosing between a substantially complete, and a substantially

incomplete, record. Which of the alternatives, he elects, matters very

little; but he must abide by the consequences of his decision, he

cannot eat his cake and have it.

When the evolutionist appeals to the facts of palæontology, it goes

without saying that he does so in the hope of showing that the

differences, which divide modern species of plants and animals,

diminish as we go backward in time, until the stage of identity is

reached in the unity of a common ancestral type. Hence from the very

nature of the argument, which he is engaged in constructing, he is

compelled to resort to intermediate types as evidence of the continuity

of allied species with the hypothetical ancestor, or common type,

whence they are said to have diverged. Now, even supposing that his

efforts in this direction were attended with a complete measure of

success, evidence of this kind would not of itself, as we shall see,

suffice to demonstrate the common origin of the extremes, between

which a perfect series of intergradent types can be shown to mediate.

Unquestionably, however, unless such a series of intergradent fossil

species can be adduced as evidence of the assumed transition, the

presumption is totally against the hypothesis of transformism.

Now, as a matter of fact, the geological record rarely offers any

evidence of the existence in the past of intermediate species. For

those, who have implicit confidence in the _time-value_ of geological

“formations,” there are indications of a general advance from lower to

higher forms, but, even so, there is little to show that this seeming

progress is to be interpreted as an increasing divergence from common

ancestral types. With but few exceptions, the fossil record fails to

show any trace of transitional links. Yet pedigrees made up of diverse

genera are poor evidence for filiation or genetic continuity, so long

as no intermediate species can be found to bridge the chasm of generic

difference. By intermediate species, we do not mean the fabulous

“generalized type.” Annectants of this kind are mere abstractions,

which have never existed, and never could have existed. We refer rather

to actual fossil types separated from one another by differences not

greater than specific; for “not until we have linked species into

lineages,” can fossil pedigrees lay claim to serious attention.

But let us suppose the case for evolution to be ideally favorable, and

assume that in every instance we possessed a perfect gradation of forms

between two extremes, such, for example, as occurs in the Ammonite

series, even then we would be far from having a true demonstration of

the point at issue. Bateson has called our attention to the danger of

confounding sterile and instable _hybrids_ with intergradent species.

“Examine,” he says, “any two thoroughly distinct species which meet

each other in their distribution, as for instance, _Lychnis diurna_

and _vespertina_ do. In areas of overlap are many intermediate forms.

These used to be taken to be transitional steps, and the specific

distinctness of _vespertina_ and _diurna_ was on that account

questioned. Once it is known that these supposed intergrades are merely

mongrels between the two species the transition from one to the other

is practically beyond our powers of imagination to conceive. If both

these can survive, why has their common parent perished? Why, when

they cross, do they not reconstruct it instead of producing partially

sterile hybrids? I take this example to show how entirely the facts

were formerly misrepresented.” (_Heredity_, Smithson. Inst. Rpt. for

1915, p. 369.)

Similarly, T. H. Morgan has shown, with reference to _mutants_,

the fallacy of inferring common descent from the phenomenon of

intergradence, and what holds true for a series of intergradent mutants

would presumably also hold true of a series of intergradent species,

could such a series be found and critically distinguished from hybrid

and mutational intermediates. In short, the Darwinian deduction of

common origin from the existence of intergradence must now be regarded

as a thoroughly discredited argument. “Because we can often arrange

the series of structures in a line extending from the very simple

to the more complex, we are apt to become unduly impressed by this

fact and conclude that if we found the complete series we should find

all the intermediate steps and that they have arisen in the order

of their complexity. This conclusion is not necessarily correct.”

(“A Critique of the Theory of Evolution,” p. 9.) Having cited such

a series of gradational mutations ranging between the long-winged,

and completely wingless condition, in the case of the Vinegar Fly

(_Drosophila melanogaster_), as well as two similar graded series based

on pigmentation and eye color, he concludes: “These types, with the

fluctuations that occur within each type, furnish a complete series of

gradations; yet historically they have arisen independently of each

other. Many changes in eye color have appeared. As many as thirty or

more races differing in eye color are now maintained in our cultures.

Some of them are so similar that they can scarcely be separated from

each other. It is easily possible beginning with the darkest eye color,

sepia, which is a deep brown, to pick out a perfectly graded series

ending with pure white eyes. But such a serial arrangement would give

a totally false idea of the way the different types have arisen; and

any conclusion based on the existence of such a series might very well

be entirely erroneous, for the fact that such a series exists bears

no relation to the order in which its members have appeared.” (_Op.

cit._, pp. 12, 13.) Such facts must give us pause in attaching undue

importance to phenomena like the occurrence of a gradual complication

of sutures in the Chalk Ammonites, particularly as parallel series

of perfectly similar sutures occurs “by convergence” in the fossil

Ceratites, which have no genetic connection with the Ammonites. (Cf.

Woods’ “Palæontology,” 5th ed., p. 16.)

But, if even mutational and specific intergradents are not sufficient

evidence of common ancestry, what shall we say of a discontinuous

series, whose links are separate genera, orders, or even classes,

instead of species. Even the most enthusiastic transformist is forced

to admit the justice of our insistence that the gaps which separate the

members of a series must be reduced from differences of the generic,

to differences of the specific, order, before that series can command

any respect as hypothetical “genealogy.” “You will have observed,” says

F. A. Bather, “that the precise methods of the modern palæontologist,

on which this proof is based, are very different from the slap-dash

conclusions of forty years ago. The discovery of _Archæopteryx_, for

instance, was thought to prove the evolution of birds from reptiles.

No doubt it rendered that conclusion extremely probable, especially

if the major promise—that evolution was the method—were assumed. But

the fact of evolution is precisely what men were then trying to prove.

These jumpings from class to class or from era to era, by aid of a few

isolated stepping-stones, were what Bacon calls anticipations “hasty

and premature but very effective, because as they are collected from a

few instances, and mostly from those which are of familiar occurrence,

they immediately dazzle the intellect and fill the imagination.” (_Nov.

Org._, I, 28.) No secure step was taken until the modern palæontologist

began to affiliate mutation with mutation and species with species,

working his way back, literally inch by inch, through a single small

group of strata. Only thus could he base on the laboriously collected

facts a single true interpretation; and to those who preferred the

broad path of generality his interpretations seemed, as Bacon says

they always “must seem, harsh and discordant—almost like mysteries of

faith.” ... Thus by degrees we reject the old slippery stepping-stones

that so often toppled us into the stream, and, foot by foot, we build

a secure bridge over the waters of ignorance.” (_Science_, Sept. 17,

1920, pp. 263, 264.)

We cannot share Bather’s confidence in the security of a bridge

composed of even linked species. Let such a series be never so perfect,

let the gradation be never so minute, as it might conceivably be

made, when not merely distinct species, but also hybrids, mutants

and fluctuants are available as stopgaps, the bare fact of such

intergradation tells nothing whatever concerning the problem of

genetical origin and specific relationship. The species-by-species

method does, however, represent the very minimum of requirement imposed

upon the palæontologist, who professes to construct a fossil pedigree.

But, when all is said and done, such a method, even at its best,

falls considerably short of the mark. However perfectly intergradent

a series of fossils may be, the fact remains that these petrified

remnants of former life cannot be subjected to breeding tests, and

that, in the consequent absence of genetical experimentation, we have

no means of determining the real bearing of these facts upon the

problem of interspecific relationship. Only the _somatic_ characters

of extinct floras and faunas have been conserved in the rock record of

the past, and even these are often rendered dubious, as we shall see

presently, by their imperfect state of preservation. Now, it is solely

in conjunction with breeding experiments, that somatic characters can

give us any insight into the nature of the _germinal constitution_

of an organism, which, after all, is the cardinal consideration upon

which the whole question of interspecific relationship hinges. All

inferences, therefore, regarding the descent of fossil forms are

irremediably speculative and conjectural. When we are dealing with

living forms, we can always check up the inferences based on somatic

characteristics by means of genetical experiments, and in so doing

we have found that it is as unsafe to judge of an organism from the

exclusive standpoint of its external characters as it is to judge of

a book by the cover; for, apart from the check of breeding tests, it

is impossible to say just which somatic characters are genetically

significant, and which are not. Forms externally alike may be so

unlike in germinal constitution as to be sexually incompatible; forms

externally unlike may be readily crossed without any discernible

diminution of fertility. “Who could have foreseen,” exclaims Bateson,

“that the apple and the pear—so like each other that their botanical

differences are evasive—could not be crossed together, though

species of _Antirrhinum_ (Snapdragon) so totally unlike each other

as _majus_ and _molle_ can be hybridized, as Baur has shown, without

a sign of impaired fertility?” (_Heredity_, Smithson. Inst. Rpt. for

1915, p. 370.) We cannot distinguish between alleged specific, and

merely mutational (varietal), change, nor between hybridizations and

factorial, chromosomal, or pseudo-, mutations, solely on the basis

of such external characters as are preserved for us in fossils. It

is impossible, therefore, to demonstrate trans-specific variation by

any evidence that Palæontology can supply. The palæontologist (_pace_

Osborn) is utterly incompetent to pass judgment on the problem of

interspecific relationship. As Bateson remarks: “In discussing the

physiological problem of interspecific relationship evidence of a more

stringent character is now required; and a naturalist acquainted with

genetical discoveries would be as reluctant to draw conclusions as to

the specific relationship of a series of fossils as a chemist would be

to pronounce on the nature of a series of unknown compounds from an

inspection of them in a row of bottles.” (_Science_, April 17, 1922,

p. 373.) “When the modern student of variation and heredity,” says T.

H. Morgan, “looks over the different ‘continuous’ series, from which

certain ‘laws’ and ‘principles’ have been deduced, he is struck by two

facts: that the gaps, in some cases, are enormous as compared with the

single changes with which he is familiar, and (what is more important)

that they involve numerous parts in many ways. The geneticist says to

the palæontologist, since you do not know, and from the nature of your

case can never know, whether your differences are due to one change or

to a thousand, you cannot with certainty tell us anything about the

hereditary units which have made the process of evolution possible.”

(_Op. cit._, pp. 26, 27.) And without accurate knowledge on this

subject, we may add, there is no possibility of demonstrating specific

change or genetic relationship in the case of any given fossil.

In our discussion of the third defect in the fossil “evidence,”

allusion was made to a fourth, namely, its imperfect state of

preservation. The stone record of bygone days has been so defaced by

the metamorphism of rocks, by the solvent action of percolating waters,

by erosion, weathering and other factors of destruction, that, like a

faded manuscript, it becomes, even apart from its actual _lacunae_,

exceedingly difficult to decipher. So unsatisfactory, indeed, is the

condition of the partially obliterated facts that human curiosity,

piqued at their baffling ambiguity, calls upon human imagination

to supply what observation itself fails to reveal. Nor does the

invitation remain unheeded. Romance hastens to the rescue of uncertain

Science, with an impressive display of “reconstructed fossils,” and

the hesitation of critical caution is superseded by the dogmatism of

arbitrary assumption. Scattered fragments of fossilized bones are

integrated into skeletons and clothed by the magic of creative fancy

with an appropriate musculature and flesh, reënacting for us the

marvelous vision of Ezekiel: “And the bones came together, each one to

its joint. And I beheld and, lo, there were sinews upon them, and the

flesh came upon them: and the skin was stretched over them.” (Chap.

XXXVII, 7, 8.) “It is also true,” says Osborn (who, like Haeckel,

evinces a veritable mania for “retouching” incomplete facts), “that

we know the mode of origin of the human species; our knowledge of

human evolution has reached a point not only where a number of links

are thoroughly known but the characters of the missing links can be

very clearly predicated.” (_Science_, Feb. 24, 1922.) We will not

dispute his contention; for it is perfectly true, that, in each and

every case, all the missing details can be so exactly predicated that

the resulting description might well put to shame the account of a

contemporary eyewitness. The only difficulty is that such predication

is the fruit of pure imagination. Scientific reconstructions, whether

in the literary, plastic, or pictorial, form, are no more scientific

than historical novels are historical. Both are the outcome of a

psychological weakness in the human makeup, namely, its craving for a

“finished picture”—a craving, however, that is never gratified save at

the expense of the fragmentary basis of objective fact.[7]

[7] See Addenda.

In calling into question, however, the scientific value of the

so-called “scientific reconstruction,” so far as its pretensions to

precision and finality are concerned, it is not our intention to

discredit those tentative restorations based upon Cuvier’s Law of

Correlation, provided they profess to be no more than provisional

approximations. Many of the structural features of organisms are

physiologically interdependent, and there is frequently a close

correlation among organs and organ-systems, between which no causal

connection or direct physiological dependence is demonstrable. In

virtue of this principle, one structural feature may connote another,

in which case it would be legitimate to supply by inference any

missing structure implied in the actual existence of its respective

correlative. But if any one imagines that the law of correlation

enables a scientist to restore the lost integrity of fossil types

with any considerable degree of accuracy and finality, he greatly

overestimates the scope of the principle in question. At best it is

nothing more than an empirical generalization, which must not be

pressed to an extent unwarranted by the inductive process, that first

established it. “Certain relations of structure,” says Bather, “as

of cloven hoofs and horns with a ruminant stomach, were observed, but

as Cuvier himself insisted, the laws based on such facts were purely

empirical.” (_Science_, Sept. 17, 1920, p. 258.) The palæontologist,

then, is justified in making use of correlation for the purpose of

reconstructing a whole animal out of a few fragmentary remains, but to

look for anything like photographic precision in such “restorations” of

extinct forms is to manifest a more or less complete ignorance of the

nature and scope of the empirical laws, upon which they are based.

The imprudence of taking these “reconstructions” of extinct forms

too seriously, however, is inculcated not merely by theoretical

considerations, but by experience as well. Even in the case of the

mammoth, a comparatively recent form, whose skeletal remains had

been preserved more completely and perfectly than those of other

fossil types, the discovery of a complete carcass buried in the ice

of the Siberian “taiga” on the Beresovka river showed the existing

restorations to be false in important respects. All, without exception,

stood in need of revision, proving, once and for all, the inadequacy

of fossil remains as a basis for exact reconstruction. E. Pfizenmayer,

a member of the investigating expedition, comments on the fact as

follows: “In the light of our present knowledge of the mammoth,

and especially of its exterior, the various existing attempts at a

restoration need important corrections. Apart from the many fanciful

sketches intended to portray the exterior of the animal, all the more

carefully made restorations show the faults of the skeleton, hitherto

regarded as typical, on which they are based, especially the powerful

semicircular and upward-curved tusks, the long tail, etc.

“As these false conceptions of the exterior of the mammoth, both

written and in the form of pictures, are contained in all zoölogical

and palæontological textbooks, and even in scientific monographs, it

seems necessary to construct a more nearly correct picture, based on

our present knowledge. I have ventured on this task, because as a

member of the latest expedition for mammoth remains, I was permitted

not only to become acquainted with this newest find while still in its

place of deposit and to take part in exhuming it, but also to visit

the zoölogical museum of St. Petersburg, which is so rich in mammoth

remains, for the purpose of studying the animal more in detail.”

(Smithson. Inst. Rpt. for 1906, pp. 321, 322.) The example is but

one of many, which serve to emphasize not merely the inadequacy of

the generality of palæontological restorations, but also the extreme

difficulty which the palæontologist experiences in interpreting aright

the partially effaced record of a vanished past.

The fifth and most critical flaw in the fossil “evidence” for evolution

is to be found in the anomalies of the actual distribution of fossils

in time. It is the boast of evolutionary Palæontology that it is able

to enhance the cogency of the argument from mere structural resemblance

by showing, that, of two structurally allied forms, one is more ancient

than the other, and may, therefore, be presumed to be ancestral to the

later form. Antecedence in time is the _sine qua non_ qualification

of a credible ancestor, and, unless the relative priority of certain

organic types, as compared with others, can be established with

absolute certainty, the whole palæontological argument collapses, and

the boast of evolutionary geology becomes an empty vaunt.

Whenever the appearance of a so-called annectant type is antedated by

that of the two forms, which it is supposed to connect, this fact is,

naturally, a deathblow to its claim of being the “common ancestor,”

even though, from a purely morphological standpoint, it should

possess all the requisites of an ancestral type. Commenting upon the

statement that a certain genus “is a truly annectant form uniting the

Melocrinidae and the Platycrinidae,” Bather takes exception as follows:

“The genus in question appeared, so far as we know, rather late in the

Lower Carboniferous, whereas both Platycrinidae and Melocrinidae were

already established in Middle Silurian time. How is it possible that

the far later form should unite these two ancient families? Even a

_mésalliance_ is inconceivable.” (_Science_, Sept. 17, 1920, p. 260.)

Certainty, therefore, with respect to the comparative antiquity of

the fossiliferous strata is the indispensable presupposition of any

palæontological argument attempting to show that there is a gradual

approximation of ancient, to modern, types. Yet, of all scientific

methods of reckoning, none is less calculated to inspire confidence,

none less safeguarded from the abuses of subjectivism and arbitrary

interpretation, than that by which the relative age of the sedimentary

rocks is determined!

In order to date the strata of any given series with reference to

one another, the palæontologist starts with the principle that, in

an undisturbed area, the deeper sediments have been deposited at an

earlier period than the overlying strata. Such a criterion, however,

is obviously restricted in its application to local areas, and is

available only at regions of outcrop, where a vertical section of the

strata is visibly exposed. To trace the physical continuity, however,

of the strata (if such continuity there be) from one continent to

another, or even across a single continent, is evidently out of

the question. Hence, to correlate the sedimentary rocks of a given

region with those of another region far distant from the former,

some criterion other than stratigraphy is required. To supply this

want, recourse has been had to _index fossils_, which have now

come into general use as age-markers and means of stratigraphical

correlation, where the criterion of _superposition_ is either absent

or inapplicable. Certain fossil types are assumed to be infallibly

indicative of certain stratigraphical horizons. In fact, when it

comes to a decision as to the priority or posteriority of a given

geological formation, index fossils constitute the court of last

appeal, and even the evidences of actual stratigraphical sequence and

of physical texture itself are always discounted and explained away,

whenever they chance to conflict with the presumption that certain

fossil forms are typical of certain geological periods. If, for

example, the superposed rock contains fossils alleged to be typical

of an “earlier” stratigraphic horizon than that to which the fossils

of the subjacent rock belong, the former is pronounced to be “older,”

despite the fact that the actual stratigraphic order conveys the

opposite impression. “We still regard fossils,” says J. W. Judd, “as

the ‘medals of creation,’ and certain types of life we take to be as

truly characteristic of definite periods as the coins which bear the

image and superscription of a Roman emperor or of a Saxon king.” (Cf.

Smithson. Inst. Rpt. for 1912, p. 356.) Thus it comes to pass, in the

last analysis, that fossils, on the one hand, are dated according to

the consecutive strata, in which they occur, and strata, on the other

hand, are dated according to the fossils which they contain.

Such procedure, if not actually tantamount to a _vicious circle_,

is, to say the least, in imminent danger of becoming so. For, even

assuming the so-called empirical generalization, that makes certain

fossils typical of certain definitely-aged geological “formations,” to

be based upon induction sufficiently complete and analytic to insure

certainty, at least, in the majority of instances, and taking it for

granted that we are dealing with a case, where the actual evidence of

stratigraphy is not in open conflict with that of the index fossils,

who does not see that such a system of chronology lends itself only

too readily to manipulation of the most arbitrary kind, whenever the

pet preconceptions of the evolutionary chronologist are at stake? How,

then, can we be sure, in a given case, that a verdict based exclusively

on the “evidence” of index fossils will be reliably _objective_? It is

to be expected that the evolutionist will refrain from the temptation

to give himself the benefit of every doubt? Will there not be an

almost irresistible tendency on the part of the convinced transformist

to revise the age of any deposit, which happens to contain fossils

that, according to his theory, ought not to occur at the time hitherto

assigned?

The citation of a concrete example will serve to make our meaning

clear. A series of fresh-water strata occur in India known as the

Siwalik beds. The formation in question was originally classed

as Miocene. Later on, however, as a result, presumably, of the

embarrassing discovery of the genus _Equus_ among the fossils of

the Upper Siwalik beds, Wm. Blanford saw fit to mend matters by

distinguishing the Upper, from the Lower, beds and assigning the

former (which contain fossil horses) to the Pliocene period. The title

Miocene being restricted by this ingenious step to beds destitute

of equine remains, namely the Nahun, or Lower Siwalik, deposits,

all danger of the horse proving to be older than his ancestors

was happily averted. A mere shifting of the conventional labels,

apparently, was amply sufficient to render groundless the fear, to

which Professor A. Sedgwick had given expression in the following

terms: “The genus _Equus_ appears in the upper Siwalik beds, which

have been ascribed to the Miocene age.... If _Equus_ really existed

in the Upper Miocene, it was antecedent to some of its supposed

ancestors.” (“Students’ Textbook of Zoölogy,” p. 599.) Evidently, the

Horse must reconcile himself perforce to the pedigree assigned to him

by the American Museum of Natural History; for he is to be given but

scant opportunity of escaping it. This classic genealogy has already

entailed far too great an expenditure of time, money and erudition to

permit of any reconsideration; and should it chance, in the ironic

perversity of things, that the Horse has been so inconsiderate as to

leave indubitable traces of himself in any formation earlier than

the Pliocene, it goes without saying that the formation in question

will at once be dated ahead, in order to secure for the “ancestors”

that priority which is their due. An elastic criterion like the index

fossil is admirably adapted for readjustments of this sort, and the

evolutionist who uses it need never fear defeat. The game he plays can

never be a losing one, because he gives no other terms than: Heads I

win, tails you lose.

In setting forth the foregoing difficulties, we have purposely

refrained from challenging the cardinal dogma of orthodox palæontology

concerning the unimpeachable time-value of index fossils as

age-markers. The force of these considerations, therefore, must be

acknowledged even by the most fanatical adherents of the aforesaid

dogma. Our forbearance in this instance, however, must not be construed

as a confession that the dogma in question is really unassailable. On

the contrary, not only is it not invulnerable, but there are many and

weighty reasons for rejecting it lock, stock, and barrel.

The palæontological dogma, to which we refer, is reducible to the

following tenets: (1) The earth is swathed with fossiliferous strata,

in much the same fashion that an onion is covered with a succession of

coats, and these strata are universal over the whole globe, occurring

always in the same invariable order and characterized not by any

peculiar uniformity of external appearance, physical texture, or

mineral composition, but solely by peculiar groups of fossil types,

which enable us to distinguish between strata of different ages and

to correlate the strata of one continent with their counterparts in

another continent—“Even the minuter divisions,” says Scott, “the

substages and zones of the European Jura, are applicable to the

classification of the South American beds.” (“Introduction to Geology,”

p. 681.) (2) In determining the relative age of a given geological

formation, its characteristic fossils form the exclusive basis of

decision, and all other considerations, whether lithological or

stratigraphic, are subordinated to this—“The character of the rocks,”

says H. S. Williams, “their composition or their mineral contents have

nothing to do with settling the question as to the particular system

to which the new rocks belong. The fossils alone are the means of

correlation.” (“Geological Biology,” pp. 37, 38.)

To those habituated to the common notion that stratigraphical sequence

is the foremost consideration in deciding the comparative age of rocks,

the following statement of Sir Archibald Geikie will come as a distinct

shock: “We may even demonstrate,” he avers, “that in some mountainous

ground the strata have been turned completely upside down, if we can

show that the fossils in what are now the uppermost layers ought

properly to lie underneath those in the beds below them.” (“Textbook,”

ed. of 1903, p. 837.) In fact, the palæontologist, H. A. Nicholson,

lays it down as a general principle that, wherever the physical

evidence (founded on stratigraphy and lithology) is at variance with

the biological evidence (founded on the presence of typical fossil

organisms), the latter must prevail and the former must be ignored: “It

may even be said,” he tells us, “that in any case where there should

appear to be a clear and decisive discordance between the physical and

the palæontological evidence as to the age of a given series of beds,

it is the former that is to be distrusted rather than the latter.”

(“Ancient Life History of the Earth,” p. 40.)

George McCready Price, Professor of Geology at a denominational college

in Kansas, devotes more than fifty pages of his recent work, “The New

Geology” (1923), to an intensely destructive criticism of this dogma of

the supremacy of fossil evidence as a means of determining the relative

age of strata. To cite Price as an “authority” would, of course, be

futile. All orthodox geologists have long since anathematized him, and

outlawed him from respectable geological society. Charles Schuchert

of Yale refers to him as “a fundamentalist harboring a geological

nightmare.” (_Science_, May 30, 1924, p. 487.) Arthur M. Miller of

Kentucky University speaks of him as “the man who, while a member of no

scientific body and absolutely unknown in scientific circles, has ...

had the effrontery to style himself a ‘geologist.’” (_Science_, June

30, 1922, pp. 702, 703.) Miller, however, is just enough to admit that

he is well-informed on his subject, and that he possesses the gift of

persuasive presentation. “He shows,” says Miller, “a wide familiarity

with geological literature, quoting largely from the most eminent

authorities in this country and in Europe. Any one reading these

writings of Price, which possess a certain charm of literary style,

and indicate on the part of the author a gift of popular presentation

which makes one regret that it had not been devoted to a more laudable

purpose, must constantly marvel at the character of mind of the man who

can so go into the literature of the subject and still continue to hold

such preposterous opinions.” (_Loc. cit._, p. 702.)

In the present instance, however, our interest centers, not on the

unimportant question of his official status in geological circles,

but exclusively on the objective validity of his argument against the

chronometric value of the index fossil. All citations, therefore, from

his work will be supported, in the sequel, by collateral testimony

from other authors of recognized standing. It is possible, of course,

to inject irrelevant issues. Price, for example, follows Sir Henry

Howorth in his endeavor to substitute an aqueous catastrophe for the

glaciation of the Quaternary Ice Age, and he adduces many interesting

facts to justify his preference for a deluge. But this is neither

here nor there; for we are not concerned with the merits of his “new

catastrophism.” It is his opportune revival in modern form of the

forgotten, but extremely effective, objection raised by Huxley and

Spencer against the alleged universality of synchronously deposited

fossiliferous sediments, that constitutes our sole preoccupation here.

It is Price’s merit to have shown that, in the light of recently

discovered facts, such as “deceptive conformities” and “overthrusts,”

this objection is far graver than it was when first formulated by the

authors in question.

Mere snobbery and abuse is not a sufficient answer to a difficulty

of this nature, and we regret that men, like Schuchert, have replied

with more anger than logic. The orthodox geologist seems unnecessarily

petulant, whenever he is called upon to verify or substantiate the

foundational principles of lithic chronology. One frequently hears him

make the excuse that “geology has its own peculiar method of proof.” To

claim exemption, however, from the universal criterions of criticism

and logic is a subterfuge wholly unworthy of a genuine science, and, if

Price insists on discussing a subject, which the orthodox geologist

prefers to suppress, it is the latter, and not the former, who is

really reactionary.

Price begins by stating the issue in the form of a twofold question:

(1) How can we be sure, with respect to a given fauna (or flora), say

the Cambrian, that at one time it monopolized our globe to the complete

exclusion of all other typical faunas (or floras), say the Devonian,

or the Tertiary, of which it is assumed that they could not, by any

stretch of imagination, have been contemporaneous, on either land or

sea, with the aforesaid “older” fauna (or flora)? (2) Do the formations

(rocks containing fossils) universally occur in such a rigidly

invariable order of sequence with respect to one another, as to warrant

our being sure of the starting-point in the time-scale, or to justify

us in projecting any given local order of succession into distant

localities, for purposes of chronological correlation?

His response to the first of these questions constitutes what may be

called an aprioristic refutation of the orthodox view, by placing

the evolutionary palæontologist in the trilemma: (a) of making the

awkward confession that, except within limited local areas, he has no

means whatever of distinguishing between a geographical distribution

of coëval fossil forms among various habitats and a chronological

distribution of fossils among sediments deposited at different times;

(b) or of denying the possibility of geographical distribution in the

past, by claiming dogmatically that the world during Cambrian times,

for example, was totally unlike the modern world, of which alone we

have experimental knowledge, inasmuch as it was then destitute of

zoölogical provinces, districts, zones, and other habitats peculiar to

various types of fauna, so that the whole world formed but one grand

habitat, extending over land and sea, for a limited group of organisms

made up exclusively of the lower types of life; (c) or of reviving

the discredited onion-coat theory of Abraham Werner under a revised

biological form, which asserts that the whole globe is enveloped with

fossiliferous rather than mineral strata, whose order of succession

being everywhere the same enables us to discriminate with precision

and certainty between cases of distribution in time and cases of

distribution in space.

In his response to the second question, Professor Price adduces

numerous factual arguments, which show that the invariable order of

sequence postulated by the theory of the time-value of index fossils,

not only finds no confirmation in the actual or concrete sequences

of fossiliferous rocks, but is often directly contradicted thereby.

“Older” rocks may occur above “younger” rocks, the “youngest” may

occur in immediate succession to the “oldest,” Tertiary rocks may be

crystalline, consolidated, and “old in appearance,” while Cambrian

and even pre-Cambrian rocks sometimes occur in a soft, incoherent

condition, that gives them the physical appearance of being as young

as Pleistocene formations. These exceptions and objections to the

“invariable order” of the fossiliferous strata accumulate from day to

day, and it is only by means of Procrustean tactics of the most drastic

sort that the facts can be brought into any semblance of harmony with

the current dogmas, which base geology upon evolution rather than

evolution upon geology.

Price, then, proposes for serious consideration the possibility that

Cretaceous dinosaurs and even Tertiary mammals may have been living on

the land at the same time that the Cambrian graptolites and trilobites

were living in the seas. “Who,” he exclaims, “will have the hardihood,

the real dogmatism to affirm in a serious way that Cambrian animals

and seaweeds were for a long time the only forms of life existing

anywhere on earth?” Should we, nevertheless, make bold enough to aver

that for countless centuries a mere few of the lower forms of life

monopolized our globe, as one universal habitat unpartitioned into

particular biological provinces or zones, we are thereupon confronted

with two equally unwelcome alternatives. We must either fly in the

face of experience and legitimate induction by denying the existence

in the past of anything analogous to our present-day geographical

distribution of plants and animals into various biological provinces,

or be prepared to show by what infallible criterion we are enabled

to distinguish between synchronously deposited formations indicative

of a geographical distribution according to regional diversity, and

consecutively deposited formations indicative of comparative antiquity.

The former alternative does not merit any consideration whatever.

The latter, as we shall presently see, involves us in an assumption,

for which no defense either aprioristic or factual is available. We

can, indeed, distinguish between spatial, and temporal, distribution

within the narrow limits of a single locality by using the criterion

of superposition; for in regions of outcrop, where one sedimentary

rock overlies another, the obvious presumption is that the upper rock

was deposited at a later date than the lower rock. But the criterion

of superposition is not available for the correlation of strata in

localities so distant from each other that no physical evidence of

stratigraphic continuity is discernible. Moreover the induction, which

projects any local order of stratigraphical sequence into far distant

localities on the sole basis of fossil taxonomy, is logically unsound

and leads to conclusions at variance with the actual facts. Hence the

alleged time-value of index fossils becomes essentially problematic,

and affords no basis whatever for scientific certainty.

As previously stated, the sequence of strata is visible only in regions

of outcrop, and nowhere are we able to see more than mere parts of two

or, at most, three systems associated together in a single locality.

Moreover, each set of beds is of limited areal extent, and the limits

are frequently visible to the eye of the observer. In any case, their

visible extent is necessarily limited. It is impossible, therefore, to

correlate the strata of one continent with those of another continent

by tracing stratigraphic continuity. Hence, in comparing particular

horizons of various ages and in distinguishing them from other horizons

over large areas, we are obliged to substitute induction for direct

observation. Scientific induction, however, is only valid when it

rests upon some universal uniformity or invariable sequence of nature.

Hence, to be specific, the assumption that the time-scale based on the

European classification of fossiliferous strata is applicable to the

entire globe as a whole, is based on the further assumption that we are

sure of the universality of fossiliferous stratification over the face

of the earth, and that, as a matter of fact, fossils are always and

everywhere found in the same order of invariable sequence.

But this is tantamount to reviving, under what Spencer calls “a

transcendental form,” the exploded “onion-coat” hypothesis of Werner

(1749-1817). Werner conceived the terrestrial globe as encircled

with successive mineral envelopes, basing his scheme of universal

stratification upon that order of sequence among rocks, which he had

observed within the narrow confines of his native district in Germany.

His hypothesis, after leading many scientists astray, was ultimately

discredited and laughed out of existence. For it finally became evident

to all observers that Werner’s scheme did not fit the facts, and men

were able to witness with their own eyes the simultaneous deposition,

in separate localities, of sediments which differed radically in

their mineral contents and texture. Thus it came to pass that this

classification of strata according to their mineral nature and physical

appearance lost all value as an absolute time-scale, while the theory

itself was relegated to the status of a curious and amusing episode in

the history of scientific fiascos.

Thanks, however, to Wm. Smith and to Cuvier, the discarded onion-coat

hypothesis did not perish utterly, but was rehabilitated and bequeathed

to us in a new and more subtle form. Werner’s fundamental idea of

the universality of a given kind of deposit was retained, but his

mineral strata were replaced by fossiliferous strata, the lithological

onion-coats of Werner being superseded by the biological onion-coats

of our modern theory. The geologist of today discounts physical

appearance, and classifies strata according to their fossil, rather

than their mineral, contents, but he stands committed to the same old

postulate of universal deposits. He has no hesitation in synchronizing

such widely-scattered formations as the Devonian deposits of New

York State, England, Germany, and South America. He pieces them all

together as parts of a single system of rocks. He has no misgiving as

to the universal applicability of the European scheme of stratigraphic

classification, but assures us, in the words of the geologist, Wm. B.

Scott, that: “Even the minuter divisions, the subdivisions and zones of

the European Jura, are applicable to the classification of the South

American beds.” (“Introduction to Geology,” p. 681f.) The limestone and

sandstone strata of Werner are now things of the past, but, in their

stead, we have, to quote the criticism of Herbert Spencer, “groups of

formations which everywhere succeed each other in a given order, and

are severally everywhere of the same age. Though it may not be asserted

that these successive systems are universal, yet it seems to be tacitly

assumed that they are so.... Though probably no competent geologist

would contend that the European classification of strata is applicable

to the globe as a whole, yet most, if not all geologists, write as

though it were so.... Must we not say that though the onion-coat

hypothesis is dead, its spirit is traceable, under a transcendental

form, even in the conclusions of its antagonists.” (“Illustrations of

Universal Progress,” pp. 329-380, ed. of 1890.)

But overlooking, for the moment, the mechanical absurdity involved in

the notion of a regular succession of universal layers of sediment,

and conceding, for the sake of argument, that the substitution of

fossiliferous, for lithological, strata may conceivably have remedied

the defects of Werner’s geological time-scale, let us confine ourselves

to the one question, which, after all, is of prime importance, whether,

namely, without the aid of Procrustean tactics, the actual facts

of geology can be brought into alignment with the doctrine of an

invariable order of succession among fossil types, and its sequel,

the intrinsic time-value of index fossils. The question, in other

words, is whether or not a reliable time-scale can be based on the

facts of fossiliferous stratification as they are observed to exist in

the concrete. Price’s answer is negative, and he formulates several

empirical laws to express the concrete facts, on which he bases his

contention. The laws and facts to which he appeals may be summarized as

follows:

1. The concrete facts of geology do not warrant our singling out any

fossiliferous deposit as unquestionably the oldest, and hence we have

no reliable _starting-point_ for our time-scale, because:

(_a_) We may lay it down as an empirical law that “any kind of

fossiliferous rock (even the ‘youngest’), that is, strata belonging to

any of the systems or other subdivisions, may rest directly upon the

Archæan or primitive crystalline rocks, without any other so-called

‘younger’ strata intervening; also these rocks, Permian, Cretaceous,

Tertiary, or whatever thus reposing directly on the Archæan may be

themselves crystalline or wholly metamorphic in texture. And this

applies not alone to small points of contact, but to large areas.”

(_b_) Conversely: any kind of fossiliferous strata (even the “oldest”)

may not only constitute the surface rocks over wide areas,[8] but may

consist of loose, unconsolidated materials, thus in both position and

texture resembling the “late” Tertiaries or the Pleistocene—“In some

regions, notably in the Baltic province and in parts of the United

States,” says John Allen Howe, alluding to the Cambrian rocks around

the Baltic Sea and in Wisconsin, “the rocks still retain their

original horizontality of deposition, the muds are scarcely indurated,

and the sands are incoherent.” (Encycl. Brit., vol. V, p. 86.)

[8] “It is a common occurrence,” says Charles Schuchert, “on

the Canadian Shield to find the Archæozoic formations overlain

by the most recent Pleistocene glacial deposits, and even

these may be absent. It appears as if in such places no rocks

had been deposited, either by the sea or by the forces of the

land, since Archæozoic time, and yet geologists know that the

shield has been variously covered by sheets of sediments formed

at sundry times in the Proterozoic, Palæozoic, and, to a more

limited extent, in the Mesozoic.” (“Textbook of Geology,” ed.

of 1920, II, p. 569.) It may be remarked that, when geologists

“know” such things, they know them in spite of the facts!

A large number of striking instances are cited by Price to substantiate

the foregoing rule and its converse. The impression left is that not

only is the starting-point of the time-scale in doubt, but that, if

we were to judge the age of the rocks by their physical appearance

and position, we could not accept the conventional verdicts of

modern geology, which makes fossil evidence prevail over every other

consideration.

2. When two contiguous strata are parallel to each other, and

there is no indication of disturbance in the lower bed, nor any

evidence of erosion along the plane of contact, the two beds are

said to exhibit conformity, and this is ordinarily interpreted

by geologists as a sign that the upper bed has been laid down in

immediate sequence to the lower, and that there has been a substantial

continuity of deposition, with no long interval during which the

lower bed was exposed as surface to the agents of erosion. When

such a conformity exists, as it frequently does, between a “recent”

stratum, above, and what is said (according to the testimony of the

fossils) to be a very “ancient” stratum, below, and though the two

are so alike lithologically as to be mistaken for one and the same

formation, nevertheless, such a conformity is termed a “non-evident

disconformity,” or “deceptive conformity,” implying that, inasmuch

as the “lost interval,” representing, perhaps, a lapse of “several

million years,” is entirely unrecorded by any intervening deposition,

or any erosion, or any disturbance of the lower bed, we should not

have suspected that so great a hiatus had intervened, were it not for

the testimony of the fossils. Price cites innumerable examples, and

sums them up in the general terms of the following empirical law:

“Any sort of fossiliferous formation may occur on top of any other

‘older’ fossiliferous formation, with all the physical evidences of

perfect conformity, just as if these alleged incongruous or mismated

formations had in reality followed one another in quick succession.”

A quotation from Schuchert’s “Textbook of Geology,” (1920), may be

given by way of illustration: “The imperfection,” we read, “of the

geologic column is greatest in the interior of North America and more

so in the north than in the south. This imperfection is in many places

very marked, since an entire period or several periods may be absent.

With such great breaks in the local sections the natural assumption

is that these gaps are easily seen in the sequence of the strata,

but in many places the beds lie in such perfect conformity upon one

another that the breaks are not noticeable by the eye and can be

proved to exist only by the entombed fossils on each side of a given

bedding plane.... Stratigraphers are, as a rule, now fully aware of the

imperfections in the geologic record, but the rocks of two unrelated

formations may rest upon each other with such absolute conformability

as to be completely deceptive. For instance, in the Bear Grass quarries

at Louisville, Ky., a face of limestone is exposed in which the

absolute conformability of the beds can be traced for nearly a mile,

and yet within 5 feet of vertical thickness is found a Middle Silurian

coral bed overlain by another coral zone of Middle Devonian. The

parting between these two zones is like that between any two limestone

beds, but this insignificant line represents a stratigraphic hiatus

the equivalent of the last third of Silurian and the first of Devonian

time. But such disconformities are by no means rare, in fact are very

common throughout the wide central basin area of North America.” (_Op.

cit._, II, pp. 586-588.)

In such cases, the stratigraphical relations give no hint of any

enormous gap at the line of contact. On the contrary, there is

every evidence of unbroken sequence, and the physical appearances

are as if these supposed “geological epochs” had never occurred

in the localities, of which there is question. Everything points

to the conclusion that the alleged long intervals of time between

such perfectly conformable, and, often, lithologically identical,

formations are a pure fiction elaborated for the purpose of bolstering

up the dogma of the universal applicability of the European

classification of fossiliferous rocks. Why not take the facts as we

find them? Why resort to tortuous explanations for the mere purpose of

saving an arbitrary time-scale? Why insist on a definite time-value

for fossils, when it drives us to the extremity of discrediting the

objective evidence of physical facts in deference to the preconceptions

of orthodox geology? Were it not for theoretical considerations, these

stratigraphic facts would be taken at their face value, and the need

of saving the reputation of the fossil as an infallible time index is

not sufficiently imperative to warrant so drastic a revision of the

physical evidence.

3. The third class of facts militating against the time-value of

index fossils, are what Price describes as “deceptive conformities

turned upside down,” and what orthodox geology tries to explain away

as “thrusts,” “thrust faults,” “overthrusts,” “low-angle faulting,”

etc.[9] In instances of this kind we find the accepted order of the

fossiliferous strata reversed in such a way that the “younger” strata

are conformably overlain by “older” strata, and the “older” strata are

sometimes interbedded between “younger” strata. “In many places all

over the world,” says Price, “fossils have been found in a relative

order which was formerly thought to be utterly impossible. That is,

the fossils have been found in the ‘wrong’ order, and on such a scale

that there can be no mistake about it. For when an area 500 miles long

and from 20 to 50 miles wide is found with Palæozoic rocks on top,

or composing the mountains, and with Cretaceous beds underneath, or

composing the valleys, and running under these mountains all around,

as in the case of the Glacier National Park and the southern part of

Alberta, the old notion about the exact and invariable order of the

fossils has to be given up entirely.”

[9] Thus, to explain away “wrong sequences” of fossils, Heim

and Rothpletz postulate the great Glaurus overthrust in the

Alps, Geikie the great overthrust in Scotland, McConnell,

Campbell, and Willis a great overthrust along the eastern

front of the Rockies in Montana and Alberta, while Hayes

recognizes numerous overthrusts in the southern Appalachians.

“The deciphering of such great displacements,” says Pirrson,

speaking of thrust faults, “is one of the greatest triumphs of

modern geological research.” (“Textbook of Geology,” 1920, I,

p. 367.) Desperate measures are evidently justifiable, when it

is a question of saving the time-value of fossils!

Price formulates his third law as follows: “Any fossiliferous

formation, ‘old’ or ‘young,’ may occur conformably on any other

fossiliferous formation, ‘younger’ or ‘older.’” The corollary of this

empirical law is that we are no longer justified in regarding any

fossils as intrinsically older than other fossils, and that our present

classification of fossiliferous strata has a _taxonomic_, rather than a

_historical_, value.

Low-angle faulting is the phenomenon devised by geologists to meet

the difficulty of “inverted sequence,” when all other explanations

fail. Immense mountain masses are said to have been detached from

their roots and pushed horizontally over the surface (without

disturbing it in the least), until they came finally to rest in

perfect conformity upon “younger” strata, so that the plane of

slippage ended by being indistinguishable from an ordinary horizontal

bedding plane. These gigantic “overthrusts” or “thrust faults” are a

rather unique phenomenon. Normal faulting is always at a high angle

closely approaching the vertical, but “thrust faults” are at a low

angle closely approximating the horizontal, and there is enormous

displacement along the plane of slippage. The huge mountain masses are

said to have been first lifted up and then thrust horizontally for

vast distances, sometimes for hundreds of miles, over the face of the

land, being thus pushed over on top of “younger” rocks, so as to repose

upon the latter in a relation of perfectly conformable superposition.

R. G. McConnell, of the Canadian Survey, comments on the remarkable

similarity between these alleged “thrust planes” and ordinary

stratification planes, and he is at a loss to know why the surface

soil was not disturbed by the huge rock masses which slid over it for

such great distances. Speaking of the Bow River Gap, he says: “The

fault plane here is nearly horizontal, and the two formations, viewed

from the valley appear to succeed one another conformably,” and then

having noted that the underlying Cretaceous shales are “very soft,” he

adds that they “have suffered little by the sliding of the limestones

over them.” (_An. Rpt. 1886_, part D., pp. 33, 34, 84.) _Credat Iudaeus

Apella, non ego!_

Schuchert describes the Alpine overthrust as follows: “The movement

was both vertical and thrusting from the south and southeast, from

the southern portion of Tethys, elevating and folding the Tertiary

and older strata of the northern areas of this mediterranean into

overturned, recumbent, and nearly horizontal folds, and pushing the

southern or Lepontine Alps about 60 miles to the northward into the

Helvetic region. Erosion has since carved up these overthrust sheets,

leaving remnants lying on foundations which belong to a more northern

portion of the ancient sea. Most noted of these residuals of overthrust

masses is the Matterhorn, a mighty mountain without roots, a stranger

in a foreign geologic environment,” (Pirsson & Schuchert’s “Textbook of

Geology,” 1920, II, p. 924.)

With such a convenient device as the “overthrust” at his disposal, it

is hard to see how any possible concrete sequence of fossiliferous

strata could contradict the preconceptions of an evolutionary

geologist. The hypotheses and assumptions involved, however, are so

tortuous and incredible, that nothing short of fanatical devotion to

the theory of transformism can render them acceptable. “Examples,”

says Price, “of strata in the ‘wrong’ order were first reported from

the Alps nearly half a century ago. Since that time, whole armfuls

of learned treatises in German, in French, and in English have been

written to explain the wonderful conditions there found. The diagrams

that have been drawn to account for the strange order of the strata

are worthy to rank with the similar ones by the Ptolemaic astronomers

picturing the cycles and epicycles required to explain the peculiar

behavior of the heavenly bodies in accordance with the geocentric

theory of the universe then prevailing.... In Scandinavia, a district

some 1,120 miles long by 80 miles wide is alleged to have been pushed

horizontally eastward ‘at least 86 miles.’ (Schuchert.) In Northern

China, one of these upside down areas is reported by the Carnegie

Research Expedition to be 500 miles long.” (“The New Geology,” 1923,

pp. 633, 634.)

Nor are the epicyclic subterfuges of the evolutionary geologist

confined to “deceptive conformities” and “overthrusts.” His inventive

genius has hit upon other methods of explaining away inconvenient

facts. When, for example, “younger” fossils are found interbedded with

“older” fossils, and the discrepancy in time is not too great, he rids

himself of the difficulty of their premature appearance by calling

them a “pioneer colony.” Similarly, when a group of “characteristic”

fossils occur in one age, skip another “age,” and recur in a third,

he recognizes the possibility of “recurrent faunas,” some of these

faunas having as many as five successive “recurrences.” Clearly, the

assumption of gradual approximation and the dogma that the lower

preceded the higher forms of life are things to be saved at all costs,

and it is a foregone conclusion that no facts will be suffered to

conflict with these irrevisable articles of evolutionary faith. “What

is the use,” exclaims Price, “of pretending that we are investigating

a problem of natural science, if we already know beforehand that the

lower and more generalized forms of animals and plants came into

existence first, and the higher and the more specialized came only long

afterwards, and that specimens of all these successive types have been

pigeonholed in the rocks in order to help us illustrate this wonderful

truth?” (_Op. cit._, pp. 667, 668.)

The predominance of extinct species in certain formations is said to

be an independent argument of their great age. Most of the species of

organisms found as fossils in Cambrian, Ordovician, and Silurian rocks

are extinct, whereas modern types abound in Cretaceous and Tertiary

rocks. Hence it is claimed that the former must be vastly older than

the latter. But this argument gratuitously assumes the substantial

perfection of the stone record of ancient life and unwarrantedly

excludes the possibility of a sudden impoverishment of the world’s

flora and fauna as the result of a sweeping catastrophe, of which our

present species are the fortunate survivors. Now the fact that certain

floras and faunas skip entire systems of rocks to reappear only in

later formations is proof positive that the record of ancient life is

far from being complete, and we have in the abundant fossil remains of

tropical plants and animals, found in what are now the frozen arctic

regions, unmistakable evidence of a sudden catastrophic change by

which a once genial climate “was abruptly terminated. For carcasses of

the Siberian elephants were frozen so suddenly and so completely that

the flesh has remained untainted.” (Dana.) Again, the mere _fact_ of

extinction tells us nothing about the _time_ of the extinction. For

this we are obliged to fall back on the index fossil whose inherent

time-value is based on the theory of evolution and not on stratigraphy.

Hence the argument from extinct species is not an independent argument.

To sum up, therefore, the aprioristic evolutional series of fossils

is not a genuine time-scale. The only safe criterion of comparative

age is that of stratigraphic superposition, and this is inapplicable

outside of limited local areas.[10] The index fossil is a reliable

basis for the chronological correlation of beds only in case one is

already convinced on other grounds of the actuality of evolution, but

for the unbiased inquirer it is destitute of any inherent time-value.

In other words, we can no longer be sure that a given formation is

old merely because it happens to contain Cambrian fossils, nor that a

rock is young merely because it chances to contain Tertiary fossils.

Our present classification of rocks according to their fossil contents

is purely arbitrary and artificial, being tantamount to nothing more

than a mere taxonomical classification of the forms of ancient life on

our globe, irrespective of their comparative antiquity. This scheme

of classification is, indeed, universally applicable, and places can

usually be found in it for new fossiliferous strata, whenever and

wherever discovered. Its universal applicability, however, is due not

to any prevalent order of invariable sequence among fossiliferous

strata, but solely to the fact that the laws of biological taxonomy

and ecology are universal laws which transcend spatial and temporal

limitation. If a scheme of taxonomy is truly scientific, all forms of

life, whether extant or extinct, will fit into it quite readily.

[10] “All that geology can prove,” says Huxley, “is local order

of succession.” (“Discourses Biological and Geological,” pp.

279-288.)

The anomalies of spatial distribution constitute a sixth difficulty

for transformistic palæontology. In constructing a phylogeny the

most diverse and widely-separated regions are put under tribute to

furnish the requisite fossils, no heed being paid to what are now

at any rate impassable geographical barriers, not to speak of the

climatic and environmental limitations which restrict the migrations

of non-cosmopolitan species within the boundaries of narrow habitats.

Hypothetical lineages of a modern form of life are frequently

constructed from fossil remains found in two or more continents

separated from one another by immense distances and vast oceanic

expanses. When taxed with failure to plausibleize this procedure,

the evolutionist meets the difficulty by hypothecating wholesale and

devious migrations to and fro, and by raising up alleged land bridges

to accommodate plants and animals in their suppositional migrations

from one continent to another, etc.

The European horse, with his so-called ancestry interred, partly in

the Tertiary deposits of Europe, but mostly in those of North America,

is a typical instance of these anomalies in geographical distribution.

It would, of course, be preposterous to suppose that two independent

lines of descent could have fortuitously terminated in the production

of one and the same type, namely, the genus _Equus_. Moreover, to admit

for a moment that the extinct American _Equus_ and the extant European

_Equus_ had converged by similar stages from distinct origins would be

equivalent, as we have seen, to a surrender of the basic postulate that

structural similarity rests on the principle of inheritance. Nothing

remains, therefore, but to hypothecate a Tertiary land bridge between

Europe and North America.

Modern geologists, however, are beginning to resent these arbitrary

interferences with their science in the interest of biological

theories. Land bridges, they rightly insist, should be demonstrated by

means of positive geological evidence and not by the mere exigencies of

a hypothetical genealogy. Whosoever postulates a land bridge between

continents should be able to adduce solid reasons, and to assign a

mechanism capable of accomplishing the five-mile uplift necessary to

bring a deep-sea bottom to the surface of the hydrosphere. Such an

idea is extravagant and not to be easily entertained in our day, when

geologists are beginning to understand the principle of _isostasy_.

To-day, the crust of the earth, that is, the entire surface of the

lithosphere, is conceived as being constituted of earth columns,

all of which rest with equal weight upon the level of complete

compensation, which exists at a depth of some 76 miles below land

surfaces. At this depth viscous flows and undertows of the earth take

place, compensating all differences of gravitational stress. Hence the

materials constituting a mountain column are thought to be less dense

than those constituting the surrounding lowland columns, and for this

reason the mountains are buoyed up above the surrounding landscape. The

columns under ocean bottoms, on the contrary, are thought to consist

of heavy materials like basalt, which tend to depress the column. To

raise a sea floor, therefore, some means of producing a dilatation of

these materials would have to be available. Arthur B. Coleman called

attention to this difficulty in his Presidential Address to the

Geological Society of America (December 29, 1915), and we cannot do

better than quote his own statement of the matter here:

“Admitting,” he says, “that in the beginning the lithosphere bulged

up in places, so as to form continents, and sagged in other places,

so as to form ocean beds, there are interesting problems presented as

to the permanence of land and seas. All will admit marginal changes

affecting large areas, but these encroachments of the sea on the

continents and the later retreats may be of quite a subordinate kind,

not implying an interchange of deep-sea bottoms and land surfaces.

The essential permanence of continents and oceans has been firmly

held by many geologists, notably Dana among the older ones, and seems

reasonable; but there are geologists, especially palæontologists, who

display great recklessness in rearranging land and sea. The trend of a

mountain range, or the convenience of a running bird, or a marsupial

afraid to wet his feet seems sufficient warrant for hoisting up any sea

bottom to connect continent with continent. A Gondwana Land arises in

place of an Indian Ocean and sweeps across to South America, so that a

spore-bearing plant can follow up an ice age; or an Atlantis ties New

England to Old England to help out the migrations of a shallow-water

fauna; or a ‘Lost Land of Agulhas’ joins South Africa and India.

“It is curious to find these revolutionary suggestions made at a

time when geodesists are demonstrating that the earth’s crust over

large areas, and perhaps everywhere, approaches a state of isostatic

equilibrium, and that isostatic compensation is probably complete at a

depth of only 76 miles” ... and (having noted the difference of density

that must exist between the continental, and submarine, earth columns)

Coleman would have us bear in mind “that to transform great areas of

sea bottom into land it would be necessary either to expand the rock

beneath by several per cent or to replace heavy rock, such as basalt,

by lighter materials, such as granite. There is no obvious way in which

the rock beneath a sea bottom can be expanded enough to lift it 20,000

feet, as would be necessary in parts of the Indian Ocean, to form a

Gondwana land; so one must assume that light rocks replace heavy ones

beneath a million square miles of ocean floor. Even with unlimited

time, it is hard to imagine a mechanism that could do the work, and

no convincing geological evidence can be brought forward to show that

such a thing ever took place.... The distribution of plants and animals

should be arranged for by other means than by the wholesale elevation

of ocean beds to make dry land bridges for them.” (Smithson. Inst. Rpt.

for 1916, pp. 269-271.)

A seventh anomaly of palæontological phylogeny is what may be described

as contrariety of direction. We are asked to believe, for example, that

in mammals racial development resulted in dimensional increase. The

primitive ancestor of mammoths, mastodons, and elephants is alleged to

have been the _Moeritherium_, “a small tapirlike form, from the Middle

Eocene Qasr-el-Sagha beds of the Fayûm in Egypt.... _Moeritherium_

measured about 3½ feet in height.” (Lull: Smithson. Inst. Rpt. for

1908, pp. 655, 656.) The ancestor of the modern horse, we are told,

was “a little animal less than a foot in height, known as _Eohippus_,

from the rocks of the Eocene age.” (Woodruff: “Foundations of Biology,”

p. 361.) In the case of insects, on the other hand, we are asked to

believe the exact reverse, namely, that racial development brought

about dimensional reduction. “In the middle of the Upper Carboniferous

periods,” says Anton Handlirsch, “the forest swamps were populated

with cockroaches about as long as a finger, dragonfly-like creatures

with a wing spread of about 2½ feet, while insects that resemble our

May flies were as big as a hand.” (“Die fossilen Insekten, und die

Phylogenie der recenten Formen,” 1908, L. c., p. 1150.) Contrasting one

of these giant palæozoic dragonflies, _Meganeura monyi_ Brongn., with

the largest of modern dragonflies, _Aeschna grandis_ L., Chetverikov

exclaims with reference to the latter: “What a pitiful pigmy it is and

its specific name (_grandis_) sounds like such a mockery.” (Smithson.

Inst. Rpt. for 1918, p. 446.) Chetverikov, it is true, proposes a

teleological reason for this progressive diminution, but the fact

remains that for dysteleological evolutionism, which dispenses with

the postulate of a Providential coördination and regulation of natural

agencies, this _diminuendo_ of the “evolving” insects stands in

irreconcilable opposition to the _crescendo_ of the “evolving” mammals,

and constitutes a difficulty which a purely mechanistic philosophy can

never surmount.

Not to prolong excessively this already protracted enumeration of

discrepancies between fossil fact and evolutionary assumption, we

shall mention, as an eighth and final difficulty, the indubitable

persistence of _unchanged_ organic types from the earliest geological

epochs down to the present time. This phenomenon is all the more

wonderful in view of the fact that the decision as to which are to be

the “older” and which the “younger” strata rests with the evolutionary

geologist, who is naturally disinclined to admit the antiquity of

strata containing modern types, and whose position as arbiter enables

him to date formations aprioristically, according to the exigencies of

the transformistic theory. Using, as he does, the absence of modern

types as an express criterion of age, and having, as it were, his pick

among the various fossiliferous deposits, one would expect him to be

eminently successful in eliminating from the stratigraphic groups

selected for senior honors all strata containing fossil types identical

with modern forms. Since, however, even the most ingenious sort of

geological gerrymandering fails to make this elimination complete, we

must conclude that the evidence for persistence of type is inescapable

and valid under any assumption.

When we speak of persistent types, we mean generic and specific,

rather than phyletic, types, although it is assuredly true that the

persistence of the great phyla, from their abrupt and contemporaneous

appearance in Cambrian and pre-Cambrian rocks down to the present day,

constitutes a grave difficulty for progressive evolution in general

and monophyletic evolution in particular. All the great invertebrate

types, such as the protozoa, the annelida, the brachiopoda, and large

crustaceans called eurypterids, are found in rocks of the Proterozoic

group, despite the damaged condition of the Archæan record, while

in the Cambrian they are represented by a great profusion of forms.

“The Lower Cambrian species,” says Dana, “have not the simplicity of

structure that would naturally be looked for in the earliest Palæozoic

life. They are perfect of their kind and highly specialized structures.

No steps from simple kinds leading up to them have been discovered; no

line from the protozoans up to corals, echinoderms, or worms, or from

either of these groups up to brachiopods, mollusks, trilobites, or

other crustaceans. This appearance of abruptness in the introduction

of Cambrian life is one of the striking facts made known by geology.”

(“Manual,” p. 487.) Thus, as we go backward in time, we find the great

organic phyla retaining their identity and showing no tendency to

converge towards a common origin in one or a few ancestral types. For

this reason, as we shall see presently, geologists are beginning to

relegate the evolutionary process to unknown depths below the explored

portion of the “geological column.” What may lurk in these unfathomed

profundities, it is, of course, impossible to say, but, if we are to

judge by that part of the column which is actually exposed to view,

there is no indication whatever of a steady progression from lower, to

higher, degrees of organization, and it takes all the imperturbable

idealism of a scientific doctrinaire to discern in such random, abrupt,

and unrelated “origins” any evidence of what Blackwelder styles “a

slow but steady increase in complexity of structure and in function.”

(_Science_, Jan. 27, 1922, p. 90.)

But, while the permanence of phyletic types excludes progress, that

of generic and specific types excludes change, and hence it is in

the latter phenomenon, especially, that the theory of transformism

encounters a formidable difficulty. Palæobotany furnishes numerous

examples of the persistence of unchanged plant forms. Ferns identical

with the modern genus _Marattia_ occur in rocks of the Palæozoic group.

Cycads indistinguishable from the extant genera _Zamia_ and _Cycas_ are

found in strata belonging to the Triassic system, etc., etc.

The same is true of animal types. In all the phyla some genera and

even species have persisted unchanged from the oldest strata down to

the present day. Among the Protozoa, for example, we have the genus

_Globigerina_ (one of the Foraminifera), some modern species of which

are identical with those found in the Cretaceous. To quote the words

of the Protozoologist, Charles A. Kofoid: “The Protozoa are found

in the oldest fossiliferous rocks and the genera of _Radiolaria_

therein conform rather closely to genera living today, while the

fossil _Dinoflagellata_ of the flints of Delitzsch are scarcely

distinguishable from species living in the modern seas. The striking

similarities of the most ancient fossil Protozoa to recent ones afford

some ground for the inference that the Protozoa living today differ but

little from those when life was young.” (_Science_, April 6, 1923, p.

397.)

The Metazoa offer similar examples of persistence. Among the

Cœlenterata, we have the genus _Springopora_, whose representatives

from the Carboniferous limestones closely resemble some of the

present-day reef builders of the East Indies. Species of the brachiopod

genera _Lingula_ and _Crania_ occurring in the Cambrian rocks are

indistinguishable from species living today, while two other modern

genera of the Brachiopoda, namely, _Rhynchonella_ and _Discina_,

are represented among the fossils found in Mesozoic formations.

_Terebratulina striata_, a fossil species of brachiopod occurring in

the rocks belonging to the Cretaceous system, is identical with our

modern species _Terebratulina caput serpentis_. Among the Mollusca such

genera as _Arca_, _Nucula_, _Lucina_, _Astarte_, and _Nautilus_ have

had a continuous existence since the Silurian, while the genera _Lima_

and _Pecten_ can be traced to the Permian. One genus _Pleurotomaria_

goes back to pre-Cambrian times. As to Tertiary fossils, Woods informs

us that “in some of the later Cainozoic formations as many as 90 per

cent of the species of mollusks are still living.” (“Palæontology,”

1st ed., p. 2.) Among the Echinodermata, two genera, _Cidaris_ (a

sea urchin) and _Pentacrinus_ (a crinoid) may be mentioned as being

persistent since the Triassic (“oldest” system of the Mesozoic group).

Among the Arthropoda, the horseshoe crab _Limulus polyphemus_ has

had a continuous existence since the Lias (_i.e._ the lowest series

of the Jurassic system). Even among the Vertebrata we have instances

of persistence. The extant Australian genus _Ceratodus_, a Dipnoan,

has been in existence since the Triassic. Among the fossils of the

Jurassic (middle system of the Mesozoic group), _Sharks_, _Rays_, and

_Chimaeroids_ occur in practically modern forms, while some of the

so-called “ganoids” are extremely similar to our present sturgeons and

gar pikes—“Some of the Jurassic fishes approximate the teleosts so

closely that it seems arbitrary to call them ganoids.” (Scott.)

The instances of persistence enumerated above are those acknowledged by

evolutionary palæontologists themselves. This list could be extended

somewhat by the addition of several other examples, but even so, it

would still be small and insufficient to tip the scales decisively

in favor of fixism. On the other hand, we must not forget that the

paucity of this list is due in large measure to the fact that our

present method of classifying fossiliferous strata was deliberately

framed with a view to excluding formations containing modern types

from the category of “ancient” beds. Moreover, orthodox palæontology

has minimized the facts of persistence to an extent unwarranted even

by its own premises. As the following considerations indicate, the

actual number of persistent types is far greater, even according to the

evolutionary time-scale, than the figure commonly assigned.

First of all, we must take into account the deplorable, if not

absolutely dishonest, practice, which is in vogue, of inventing new

names for the fossil duplicates of modern species, in order to mask or

obscure an identity which conflicts with evolutionary preconceptions.

When a given formation fails to fit into the accepted scheme by

reason of its fossil anachronisms, or when, to quote the words of

Price, “species are found in kinds of rock where they are not at all

expected, and where, according to the prevailing theories, it is

quite incredible that they should be found ... the not very honorable

expedient is resorted to of inventing a new name, specific or even

generic, to disguise and gloss over the strange similarity between them

and the others which have already been assigned to wholly different

formations.” (“The New Geology,” p. 291.) The same observation is

made by Heilprin. “It is practically certain,” says the latter, “that

numerous forms of life, exhibiting no distinctive characters of their

own, are constituted into distinct species for no other reason than

that they occur in formations widely separated from those holding

their nearest kin.” (“Geographical and Geological Distribution of

Animals,” pp. 183, 184.) An instance of this practice occurs in the

foregoing list, where a fossil brachiopod identical with a modern

species receives the new specific name “_striata_.” Its influence is

also manifest in the previously quoted apology of Scott for calling

teleost-like fish “ganoids.”

We must also take into account the imperfection of the fossil record,

which is proved by the fact that most of the acknowledged “persistent

types” listed above “skip” whole systems and even groups of “later”

rocks (which are said to represent enormous intervals of time), only

to reappear, at last, in modern times. It is evident that their

existence has been continuous, and yet they are not represented in the

intervening strata. Clearly, then, the fossil record is imperfect, and

we must conclude that many of our modern types actually did exist in

the remote past, without, however, leaving behind any vestige of their

former presence.

Again, we must frankly confess our profound ignorance with respect to

the total number and kinds of species living in our modern seas. Hence

our conventional distinction between “extinct” and “extant” species has

only a provisory value. Future discoveries will unquestionably force

us to admit that many of the species now classed as “extinct” are in

reality living forms, which must be added to our list of “persistent

types.” “It is by no means improbable,” says Heilprin, “that many of

the older genera, now recognized as distinct by reason of our imperfect

knowledge concerning their true relationships, have in reality

representatives in the modern sea.” (_Op. cit._ pp. 203, 204.)

Finally, the whole of our present taxonomy of plants and animals, both

living and fossil, stands badly in need of revision. Systematists,

as we have seen in the second chapter, base their classifications

mainly on what they regard as basic or homologous structures, in

contradistinction to superficial or adaptive characters. Both kinds

of structure, however, are purely somatic, and somatic characters,

as previously observed, are not, by themselves, a safe criterion for

discriminating between varieties and species. In the light of recent

genetical research, we cannot avoid recognizing that there has been

far too much “splitting” of organic groups on the basis of differences

that are purely fluctuational, or, at most, mutational. Moreover,

the distinction between homologous and adaptive structures is often

arbitrary and largely a matter of personal opinion, especially when

numerous specimens are not available. What the “Cambridge Natural

History” says in allusion to the Asteroidea is of general application.

“While there is considerable agreement,” we read, “amongst authorities

as to the number of families, or minor divisions of unequivocal

relationship, to be found in the class Asteroidea, there has been

great uncertainty both as to the number and limits of the orders

into which the class should be divided, and also as to the limits of

the various species. The difficulty about the species is by no means

confined to the group Echinodermata; in all cases where the attempt

is made to determine species by an examination of a few specimens

of unknown age there is bound to be uncertainty; the more so, as it

becomes increasingly evident that there is no sharp line to be drawn

between local varieties and species. In Echinodermata, however, there

is the additional difficulty that the acquisition of ripe genital cells

does not necessarily mark the termination of growth; the animals can

continue to grow and at the same time slightly alter their characters.

For this reason many of the species described may be merely immature

forms....

“The disputes, however, as to the number of orders included in the

Asteroidea proceed from a different cause. The attempt to construct

detailed phylogenies involves the assumption that one set of

structures, which we take as the mark of the class, has remained

constant, whilst the others which are regarded as adaptive, may have

developed twice or thrice. As the two sets of structures are about

of equal importance it will be seen to what an enormous extent the

personal equation enters in the determination of these questions.”

(_Op. cit._, vol. I, pp. 459, 460.)

In dealing with fossil forms, these difficulties of the taxonomist

are intensified: (1) by the sparse, badly-preserved, and fragmentary

character of fossil remains; (2) by the fact that here breeding

experiments are impossible, and hence the diagnosis based on external

characters cannot be supplemented by a diagnosis of the germinal

factors. Fossil taxonomy is, in consequence, extremely arbitrary and

unreliable. Many fossil forms classed as distinct species, or even

as distinct genera, may be nothing more than fluctuants, mutants,

hybrids, or immature stages of well-known species living today.

Again, many fossils mistaken for distinct species are but different

stages in the life-history of a single species, a mistake, which is

unavoidable, when specimens are few and the age of the specimens

unknown. The great confusion engendered in the classification of

the hydrozoa by nineteenth-century ignorance of the alternation of

hydroid and medusoid generations is a standing example of the danger

of classifying forms without a complete knowledge of the entire

life-cycle. When due allowance is made for mutation, hybridization,

metagenesis, polymorphism, age and metamorphosis, the number of

distinct fossil species will undergo considerable shrinkage. Nor must

we overlook the possibility of environmentally-induced modifications.

Many organisms, such as mollusks, undergo profound alteration as a

result of some important, and, perhaps, relatively permanent, change in

their environmental conditions, though such alterations affect only the

phenotype, and do not involve a corresponding change in the specific

genotype, _i.e._ the germinal constitution of the race.

In the degree that these considerations are taken into account the

number of “extinct” fossil species will diminish and the number of

“persistent” species will increase. This is a consummation devoutly to

be wished for, but it means that hundreds of thousands of described

species must needs be reviewed for the purpose of weeding out the

duplicates, and who will have the knowledge, the courage, or even the

span of life, necessary to accomplish so gigantic a task?

But so far as the practical purposes of our argument are concerned, the

accepted list of persistent types needs no amplification. It suffices,

as it stands, to establish the central fact (which, for the rest,

is admitted by everyone) that some generic and even specific types

have remained unchanged throughout the enormous lapse of time which

has intervened between the deposition of the oldest strata and the

advent of the present age. Our current theories, far from diminishing

the significance of this fact, tend to intensify it by computing the

duration of such persistence in millions, rather than in thousands, of

years. Now, whatever one’s views may be on the subject of transformism,

this prolonged permanence of certain genera and species is an

indubitable _fact_, which is utterly irreconcilable with a _universal

law_ of organic evolution. The theory of transformism is impotent

to explain an exception so palpable as this; for persistence and

transmutation cannot be subsumed under one and the same principle. That

which accounts for change cannot account for _unchange_. Yet unchange

is an observed fact, while the change, in this case, is an inferred

hypothesis. Hence, even if we accept the principle of transformism,

there will always be scope for the principle of permanence. The

extraordinary tenacity of type manifested by persistent genera and

species is a phenomenon deserving of far more careful study and

investigation than the evolutionally-minded scientist of today deigns

to bestow upon it. To the latter it may seem of little consequence,

but, to the genuine scientist, the actual persistence of types should

be of no less interest than their possible variability.

With these reflections, our criticism of the palæontological argument

terminates. The enumeration of its various deficiencies was not

intended as a refutation. To disprove the theory of organic evolution

is a feat beyond our power to accomplish. We can only adduce negative

evidence, whose scope is to show that the various evolutionary

arguments are inconsequential or inconclusive. We cannot rob the

theory of its intrinsic possibility, and sheer justice compels us to

confess that certain facts, like those of symbiotic preadaptation,

lend themselves more readily to a transformistic, than to a fixistic,

interpretation. On the other hand, nothing is gained by ignoring

flaws so obvious and glaring as those which mar the cogency of

palæontological “evidence.” The man who would gloss them over is

no true friend either of Science or of the scientific theory of

Evolution! They represent so many real problems to be frankly faced

and fully solved, before the palæontological argument can become a

genuine demonstration. But until such time as a demonstration of this

sort is forthcoming, the evolutionist must not presume to cram his

unsubstantiated theory down our reasonably reluctant throats. To accept

as certain what remains unproved, is to compromise our intellectual

sincerity. True certainty, which rests on the recognition of objective

necessity, will never be attainable so long as difficulties that sap

the very base of evolutionary argumentation are left unanswered; and,

as for those who, in the teeth of discordant factual evidence, profess,

nevertheless, to have certainty regarding the “fact” of evolution, we

can only say that such persons cannot have a very high or exacting

conception of what scientific certainty really means.

For the rest, it cannot even be said that the palæontological record

furnishes good circumstantial evidence that our globe has been the

scene of a process of organic evolution. In fact, so utterly at

variance with this view is the total impression conveyed by the

visible portion of the geological column, that the modern geologist

proposes, as we have seen, to probe depths beneath its lowest strata

for traces of that alleged transmutation, which higher horizons do

not reveal. There are six to eight thick terranes below the Cambrian,

we are told, and igneous masses that were formerly supposed to be

basal have turned out to be intrusions into sedimentary accumulations,

all of which, of course, is fortunate for the theory of organic

evolution, as furnishing it with a sadly needed new court of appeal.

The bottom, so to speak, has dropped out of the geological column,

and Prof. T. C. Chamberlin announces the fact as follows: “The sharp

division into two parts, a lifeless igneous base and a sedimentary

fossiliferous superstructure, has given place to the general concept

of continuity with merely minor oscillations in times and regions of

major activity. Life has been traced much below the Cambrian, but

its record is very imperfect. The recent discoveries of more ample

and varied life in the lower Palæozoic, particularly the Cambrian,

implies, under current evolutional philosophy, a very great downward

extension of life. In the judgment of some biologists and geologists,

this extension probably reaches below all the pre-Cambrian terranes

as yet recognized, though this pre-Cambrian extension is great. The

‘Azoic’ bottom has retired to depths unknown. This profoundly changes

the life aspect of the ‘column.’” (_Science_, Feb. 8, 1924, p. 128.)

All this is doubtless true, but such an appeal, from the known to the

unknown, from the actual to the possible, is not far-removed from a

confession of scientific insolvency. Life must, of course, have had

an earlier history than that recorded in the pre-Cambrian rocks. But

even supposing that some portion of an earlier record should become

accessible to us, it could not be expected to throw much light on the

problem of organic origins. Most of the primordial sediments have long

since been sapped and engulfed by fiery magmas, while terranes less

deep have, in all probability, been so metamorphosed that every trace

of their fossil contents has perished. The sub-Archæan beginnings of

life will thus remain shrouded forever in a mystery, which we have

no prospect of penetrating. Hence it is the exposed portion of the

geological column which continues and will continue to be our sole

source of information, and it is preëminently on this basis that the

evolutionary issue will have to be decided.

Yet what could be more enigmatic than the rock record as it stands?

For in nature it possesses none of that idealized integrity and

coherence, with which geology has invested it for the purpose of

making it understandable. Rather it is a mighty chaos of scattered

and fragmentary fossiliferous formations, whose baffling complexity,

discontinuity, and ambiguity tax the ingenuity of the most sagacious

interpreters. Transformism is the key to one possible synthesis, which

might serve to unify that intricate mass of facts, but it is idle to

pretend that this theory is the unique and necessary corollary of

the facts as we find them. The palæontological argument is simply a

theoretical construction which presupposes evolution instead of proving

it. Its classic pedigrees of the horse, the camel, and the elephant

are only credible when we have assumed the “fact” of evolution, and

even then, solely upon condition that they claim to approximate,

rather than assign, the actual ancestry of the animals in question.

In palæontology, as in the field of zoölogy, evolution is not a

conclusion, but an interpretation. In palæontology, otherwise than

in the field of genetics, evolution is not amenable to the check of

experimental tests, because here it deals not with that which is, but

with that which _was_. Here the sole objective basis is the mutilated

and partially obliterated record of a march of events, which no one

has observed and which will never be repeated. These obscure and

fragmentary vestiges of a vanished past, by reason of their very

incompleteness, lend themselves quite readily to all sorts of theories

and all sorts of speculations. Of the “Stone Book of the Universe”

we may say with truth that which Oliver Wendell Holmes says of the

privately-interpreted Bible, namely, that its readers take from it the

same views which they had previously brought to it. “I am, however,

thoroughly persuaded,” say the late Yves Delage, “that one is or is not

a transformist, not so much for reasons deduced from natural history,

as for motives based on personal philosophic opinions. If there existed

some other scientific hypothesis besides that of descent to explain

the origin of species, many transformists would abandon their present

opinion as not being sufficiently demonstrated.... If one takes his

stand upon the exclusive ground of the facts, it must be acknowledged

that the formation of one species from another species has not been

demonstrated at all.” (“L’herédité et les grands problèmes de la

biologie générale,” Paris, 1903, pp. 204, 322.)

II

THE PROBLEM OF ORIGINS

CHAPTER I

THE ORIGIN OF LIFE

§ 1. The Theory of Spontaneous Generation

Strictly speaking, the theory of Transformism is not concerned with the

initial production of organic species, but rather with the subsequent

differentiation and multiplication of such species by transmutation

of the original forms. This technical sense, however, is embalmed

only in the term transformism and not in its synonym evolution. The

signification of the latter term is less definite. It may be used

to denote any sort of development or origination of one thing from

another. Hence the problem of the formation of organic species is

frequently merged with the problem of the transformation of species

under the common title of evolution.

This extension of the evolutionary concept, in its widest sense, to the

problem of the origin of life on our globe is known as the hypothesis

of abiogenesis or spontaneous generation. It regards inorganic matter

as the source of organic life not merely in the sense of a _passive

cause_, out of which the primordial forms of life were produced, but

in the sense of an _active cause_ inasmuch as it ascribes the origin

of life to the exclusive agency of dynamic principles inherent in

inorganic matter, namely, the physicochemical energies that are native

to mineral matter. Life, in other words, is assumed to have arisen

spontaneously, that is, by means of a synthesis and convergence of

forces resident in inorganic matter, and not through the intervention

of any exterior agency.

The protagonists of spontaneous generation, therefore, assert not

merely a passive, but an active, evolution of living, from lifeless

matter. As to the fact of the origin of the primal organisms from

inorganic matter, there is no controversy whatever. All agree that, at

some time or other, the primordial plants and animals emanated from

inorganic matter. The sole point of dispute is whether they arose from

inorganic matter by active evolution or simply by passive evolution.

The passive evolution of mineral matter into plants and animals is an

everyday occurrence. The grass assimilates the nitrates of the soil,

and is, in turn, assimilated by the sheep, whose flesh becomes the food

of man, and mineral substance is thus finally transformed into human

substance. In the course of metabolic processes, the inorganic molecule

may doff its mineral type and don, in succession, the specificities of

plant, animal, and human protoplasm; and this transition from lower

to higher degrees of perfection may be termed an evolution. It is

an ascent of matter from the lowermost grade of an inert substance,

through the intermediate grades of vegetative and animal life, up

to the culminating and ultimate term of material perfection, in

the partial constitution of a human nature and personality, in the

concurrence as a coagent in vegetative and sensile functions, and

in the indirect participation, as instrument, in the higher psychic

functions of rational thought and volition.

At the present time, the inorganic world is clearly the exclusive

source of all the matter found in living beings. All living beings

construct their bodies out of inorganic substances in the process of

nutrition, and render back to the inorganic world, by dissimilation and

death, whatever they have taken from it. We must conclude, therefore,

the matter of the primordial organisms was likewise derived from the

inorganic world. But we are not warranted in concluding that this

process of derivation was an active evolution. On the contrary, all

evidence is against the supposition that brute matter is able to evolve

of itself into living matter. It can, indeed, be transformed into

plants, animals, and men through the action of an appropriate external

agent (_i.e._ solely through the agency of the living organism), but

it cannot acquire the perfections of living matter by means of its

own inherent powers. It cannot vitalize, or sensitize, itself through

the unaided activity of its own physicochemical energies. Only when

it comes under the superior influence of preëxistent life can it

ascend to higher degrees of entitive perfection. It does not become

of itself life, sensibility, and intelligence. It must first be drawn

into communion with what is already alive, before it can acquire life

and sensibility, or share indirectly in the honors of intelligence (as

the substrate of the cerebral imagery whence the human mind abstracts

its conceptual thought). Apart from this unique influence, inorganic

matter is impotent to raise itself in the scale of existence, but, if

captured, molded, and transmuted by a living being, it may progress to

the point of forming with the human soul one single nature, one single

substance, one single person. The evolution of matter exemplified in

organic metabolism is obviously passive, and such an evolution of

the primal organisms out of non-living matter even the opponents of

the hypothesis of spontaneous generation concede. But spontaneous

generation implies an active evolution of the living from the lifeless,

and this is the point around which the controversy wages. It would, of

course, be utterly irrational to deny to the Supreme Lord and Author of

Life the power of vivifying matter previously inanimate and inert, and

hence the origin of organic life from inorganic matter by a formative

(not creative) act of the Creator is the conclusion to which the denial

of abiogenesis logically leads.

The hypothesis of spontaneous generation is far older than the theory

of transformism. It goes back to the Greek predecessors of Aristotle,

at least, and may be of far greater antiquity. It was based, as is well

known, upon an erroneous interpretation of natural facts, which was

universally accepted up to the close of the 17th century. As we can

do no more than recount a few outstanding incidents of its long and

interesting history here, the reader is referred to the VII chapter of

Wasmann’s “Modern Biology” and the VIII chapter of Windle’s “Vitalism

and Scholasticism” for the details which we are obliged to omit.

§ 2. The Law of Genetic Continuity—

From time immemorial the sudden appearance of maggots in putrescent

meat had been a matter of common knowledge, and the ancients were

misled into regarding the phenomenon as an instance of a _de novo_

origin of life from dead matter. The error in question persisted until

the year 1698, when it was decisively disproved by a simple experiment

of the Italian physician Francesco Redi. He protected the meat from

flies by means of gauze. Under these conditions, no maggots appeared

in the meat, while the flies, unable to reach the meat, deposited

their eggs on the gauze. Thus it became apparent that the maggots were

larval flies, which emerged from fertilized eggs previously deposited

in decaying meat by female flies. Antonio Vallisnieri, another

Italian, showed that the fruit-fly had a similar life-history. As a

result of these discoveries, Redi rejected the theory of spontaneous

generation and formulated the first article of the Law of Genetic Vital

Continuity: _Omne vivum ex vivo_.

Meanwhile, the first researches conducted by means of the newly

invented compound microscope disclosed what appeared to be fresh

evidence in favor of the discarded hypothesis. The unicellular

organisms known as infusoria were found to appear suddenly in hay

infusions, and their abrupt appearance was ascribed to spontaneous

generation. Towards the end of the 18th century, however, a Catholic

priest named Lazzaro Spallanzani refuted this new argument by

sterilizing the infusions with heat and by sealing the containers as

protection against contamination by floating spores or cysts. After

the infusions had been boiled for a sufficient time and then sealed,

no organisms could be found in them, no matter how long they were kept.

We now know that protozoa and protophytes do not originate _de novo_ in

infusions. Their sudden appearance in cultures is due to the deposition

of spores or cysts from the air, etc.

The possibility that the non-germination of life in sterilized

infusions kept in sealed containers might be due to the absence of

oxygen, removed by boiling and excluded by sealing, left open a

single loophole, of which the 19th century defenders of abiogenesis

proceeded to avail themselves. Pasteur, however, by employing

sterilized cultures, which he aerated with filtered air exclusively,

succeeded in depriving his opponents of this final refuge, and

thereby completely demolished the last piece of evidence in favor

of spontaneous generation. Prof. Wm. Sydney Thayer, in an address

delivered at the Sorbonne, May 22, 1923, gives the following account

of Pasteur’s experiments in this field: “Then, naturally (1860-1876)

came the famous studies on spontaneous generation undertaken against

the advice of his doubting masters, Biot and Dumas. On the basis of

careful and well-conceived experiments he demonstrated the universal

presence of bacteria in air, water, dust; he showed the variation in

different regions of the bacterial content of the air; he demonstrated

the permanent sterility of media protected from contamination, and he

insisted on the inevitable derivation of every living organism from

one of its kind. ‘No,’ he said, ‘there is no circumstance known today

which justifies us in affirming that microscopic organisms have come

into the world, without parents like themselves. Those who made this

assertion have been the playthings of illusions or ill-made experiments

invalidated by errors which they have not been able to appreciate or

to avoid.’ In the course of these experiments he demonstrated the

necessity of reliable methods of sterilization for instruments or

culture media, of exposure for half an hour to moist heat at 120° or to

dry air at 180°. And behold! our modern procedures of sterilization

and the basis of antiseptic surgery.” (_Science_, Dec. 14, 1923, p.

477.) Pasteur brought to a successful completion the work of Redi and

Spallanzani. Henceforth spontaneous generation was deprived of all

countenance in the realm of biological fact.

Meanwhile, the cytologists and embryologists of the last century

were adding article after article to the law of genetic cellular

continuity, thus forging link by link the fatal chain of severance

that inexorably debars abiogenesis from the domain of natural science.

With the formulation of the great Cell Theory by Schleiden and Schwann

(1838-1839), it became clear that the cell is the fundamental unit

of organization in the world of living matter. It has proved to be,

at once, the simplest organism capable of independent existence and

the basic unit of structure and function in all the more complex

forms of life. The protists (unicellular protozoans and protophytes)

consist each of a single cell, and no simpler type of organism is

known to science. The cell is the building brick out of which the

higher organisms or metists (_i.e._ the multicellular and tissued

metazoans and metaphytes) are constructed, and all multicellular

organisms are, at one time or other in their career, reduced to the

simplicity of a single cell (_v.g._ in the zygote and spore stages).

The somatic or tissue cells, which are associated in the metists to

form one organic whole, are of the same essential type as germ cells

and unicellular organisms, although the parallelism is more close

between the unicellular organism and the germ cell. The germ cell, like

the protist, is equipped with all the potentialities of life, whereas

tissue cells are specialized for one function rather than another. The

protist is a generalized and physiologically-balanced cell, one which

performs all the vital functions, and in which the suppression of one

function leads to the destruction of all the rest; while the tissue

cell is a specialized and physiologically-unbalanced cell limited to

a single function, with the other vital functions in abeyance (though

capable of manifesting themselves under certain circumstances).

Normally, therefore, the tissue cell is functionally incomplete, a part

and not a whole, whereas the protist is an independent individual,

being, at once, the highest type of cell and the lowest type of

organism.

According to the classic definition of Franz Leydig and Max Schultze,

the cell is a mass of protoplasm containing a nucleus, both protoplasm

and nucleus arising through division of the corresponding elements of

a preëxistent cell. In this form the definition is quite general and

applies to all cells, whether tissue cells, germ cells, or unicellular

organisms. Moreover, it embodies two principles which still further

determine the law of genetic cellular continuity, namely: _Omnis

cellula ex cellula_, enunciated by Virchow in 1855, and Flemming’s

principle: _Omnis nucleus ex nucleo_, proclaimed in 1882. In this way,

Cytology supplemented Redi’s formula that every living being is from

a preëxistent living being, by adding two more articles, namely, that

every living cell is from a preëxistent cell, and every new cellular

nucleus is derived by division from a preëxistent cellular nucleus. Now

neither the nucleus nor the cell-body (the cytoplasm or extranuclear

area of the cell) is capable of an independent existence. The

cytoplasm of the severed nerve fibre, when it fails to reëstablish its

connection with the neuron nucleus, degenerates. The enucleated amœba,

though capable of such vital functions as depend upon destructive

metabolism, can do nothing which involves constructive metabolism, and

is, therefore, doomed to perish. The sperm cell, which is a nucleus

that has sloughed off most of its cytoplasm, disintegrates, unless

it regains a haven in the cytoplasm of the egg. Life, accordingly,

cannot subsist in a unit more simply organized than the cell. No

organism lives which is simpler than the cell, and the origin of all

higher forms of life is reducible, as we shall see, to the origin of

the cell. Consequently, new life can originate in no other way than

by a process of cell-division. All generation or reproduction of new

life is dependent upon the division of the cell-body and nucleus of a

preëxistent living cell.

Haeckel, it is true, has attempted to question the status of the cell

as the simplest of organisms, by alleging the existence of cytodes

(non-nucleated cells) among the bacteria and the blue-green algæ.

Further study, however, has shown that bacteria and blue-green algæ

have a distributed nucleus, like that of certain ciliates, such as

_Dileptus gigas_ and _Trachelocerca_. In such forms the entire cell

body is filled with scattered granules of chromatin called chromioles,

and this diffuse type of nucleus seems to be the counterpart of the

concentrated nuclei found in the generality of cells. At any rate,

there is a temporary aggregation of the chromioles at critical stages

in the life-cycle (such as cell-division), and these scattered

chromatin granules undergo division, although their distribution to

the daughter-cells is not as regular as that obtaining in mitosis. All

this is strongly suggestive of their nuclear nature, and cells with

distributed nuclei cannot, therefore, be classified as cytodes. In

fact, the polynuclear condition is by no means uncommon. _Paramœcium

aurelia_, for example, has a macronucleus and a micronucleus, and

the _Uroleptus mobilis_ has eight macronuclei and from two to four

micronuclei. The difference between the polynuclear and diffuse

condition seems to be relatively unimportant. In fact, the distributed

nucleus differs from the morphological nucleus mainly in the absence

of a confining membrane. From the functional standpoint, the two

structures are identical. Hence the possession of a nucleus or its

equivalent is, to all appearances, a universal characteristic of cells.

Haeckel’s “cytodes” have proved to be purely imaginary entities. The

verdict of modern cytologists is that Shultze’s definition of the cell

must stand, and that the status of the cell as the simplest of organic

units capable of independent existence is established beyond the

possibility of prudent doubt.

With the progressive refinement of microscopic technique, it has become

apparent that the law of genetic continuity applies not merely to the

cell as a whole and to its major parts, the nucleus and the cell-body,

but also to the minor components or organelles, which are seen to

be individually self-perpetuating by means of growth and division.

The typical cell nucleus, as is well known, is a spherical vesicle

containing a semisolid, diphasic network of basichromatin (formerly

“chromatin”) and oxychromatin (linin) suspended in more fluid medium

or ground called nuclear sap. When the cell is about to divide, the

basichromatin resolves itself into a definite number of short threads

called chromosomes. Now, Boveri found that, in the normal process of

cell-division known as mitosis, these nuclear threads or chromosomes

are each split lengthwise and divided into two exactly equivalent

halves, the resulting halves being distributed in equal number to the

two daughter-cells produced by the division of the original cell.

Hence, in the year 1903, Boveri added a fourth article to the law of

genetic vital continuity, namely: _Omne chromosoma ex chromosomate_.

But the law in question applies to cytoplasmic as well as nuclear

components. In physical appearance, the cell-body or cytoplasm

resembles an emulsion with a clear semiliquid external phase called

hyaloplasm and an internal phase consisting mainly of large spheres

called macrosomes and minute particles called microsomes, all of which,

together with numerous other formed bodies, are suspended in the clear

hyaloplasm (hyaline ground-substance). Now certain of these cytoplasmic

components have long been known to be _self-perpetuating_ by means

of growth and division, maintaining their continuity from cell to

cell. The plastids of plant cells, for example, divide at the time of

cell-division, although their distribution to the daughter-cells does

not appear to be as definite and regular as that which obtains in the

case of the chromosomes. Similarly, the centrioles or division-foci

of animal cells are self-propagating by division, but here the

distribution to the daughter-cells is exactly equivalent and not at

random as in the case of plastids. In the light of recent research

it looks as though two other types of cytoplasmic organelles must be

added to the list of cellular components, which are individually

self-perpetuating by growth and division, namely, the chondriosomes

and the Golgi bodies—“both mitochondria and Golgi bodies are able to

assimilate, grow, and divide in the cytoplasm.” (Gatenby.) Wilson is

of opinion that the law of genetic continuity may have to be extended

even to those minute granules and particles of the cytosome, which were

formerly thought to arise _de novo_ in the apparently structureless

hyaloplasm. Speaking of the emulsified appearance of the starfish and

sea urchin eggs, he tells us that their protoplasm shows “a structure

somewhat like that of an emulsion, consisting of innumerable spheroidal

bodies suspended in a clear continuous basis or hyaloplasm. These

bodies are of two general orders of magnitude, namely: larger spheres

or macrosomes rather closely crowded and fairly uniform in size, and

much smaller microsomes irregularly scattered between the macrosomes,

and among these are still smaller granules that graduate in size

down to the limit of vision with any power (_i.e._ of microscope)

we may employ.” (_Science_, March 9, 1923, p. 282.) Now, the limit

of microscopic vision by the use of the highest-power oil-immersion

objectives is one-half the length of the shortest waves of visible

light, that is, about 200 submicrons (the submicron being one millionth

of a millimeter). Particles whose diameter is less than this cannot

reflect a wave of light, and are, therefore, invisible so far as the

microscope is concerned. By the aid of the ultramicroscope, however,

we are enabled to see the halos formed by particles not more than four

submicrons in diameter, which, however, represents the limit of the

ultramicroscope, and is the diameter hypothetically assigned to the

protein multimolecule. Since, therefore, we find the particles in the

protoplasm of the cell body graduating all the way down to the limit

of this latter instrument, and since on the very limit of microscopic

vision we find such minute particles as the centrioles “capable of

self-perpetuation by growth and division, and of enlargement to form

much larger bodies,” we cannot ignore the possibility that the

ultramicroscopic particles may have the same powers and may be the

sources or “formative foci” of the larger formed bodies, which were

hitherto thought to arise _de novo_.

Certainly, pathology, as we shall see, tells us of ultramicroscopic

disease-germs, which are capable of reproduction and maintenance of a

specific type, and experimental genetics makes us aware of a linear

alignment of submicroscopic genes in the nuclear chromosomes, each

gene undergoing periodic division and perpetual transmission from

generation to generation. The cytologist, therefore, to quote the words

of Wilson, “cannot resist the evidence that the appearance of a simple

homogeneous colloidal substance is deceptive; that it is in reality a

complex, heterogeneous, or polyphasic system. He finds it difficult to

escape the conclusion, therefore, that the visible and the invisible

components of the protoplasmic system differ only in their size and

degree of dispersion; that they belong to a single continuous series,

and that the visible structure of protoplasm may give us a rough

magnified picture of the invisible.” (_Ibidem_, p. 283.)

It would seem, therefore, that we must restore to honor, as the fifth

article of the law of cellular continuity, the formula, which Richard

Altmann enunciated on purely speculative grounds in 1892, but which

the latest research is beginning to place on a solid factual basis,

namely: _Omne granulum ex granulo_. “For my part,” says the great

cytologist, Wilson, “I am disposed to accept the probability that

many of these particles, as if they were submicroscopical plastids,

may have a persistent identity, perpetuating themselves by growth and

multiplication without loss of their specific individual type.” And

he adds that the facts revealed by experimental embryology (_e.g._,

the existence of differentiated zones of specific composition in

the cytoplasm of certain eggs) “drive us to the conclusion that the

submicroscopical components of the hyaloplasm are segregated and

distributed according to an ordered system.” (_Ibidem_, p. 283.)

The structure of the cell has often been likened to a heterogeneous

solution, that is, to a complex polyphasic colloidal system, but this

power of perpetual division and orderly assortment possessed by the

cell as a whole and by its single components is the unique property

of the living protoplasmic system, and is never found in any of the

colloidal systems known to physical chemistry, be they organic or

inorganic.

Cells, then, originate solely by division of preëxistent cells and even

the minor components of the cellular system originate in like fashion,

namely: by division of their respective counterparts in the preëxistent

living cell. Here we have the sum and substance of the fivefold law of

genetic continuity, whose promulgation has relegated the hypothesis

of spontaneous generation to the realms of empty speculation. Waiving

the possibility of an _a priori_ argument, by which abiogenesis might

be positively excluded, there remains this one consideration, which

alone is scientifically significant, that, so far as observation goes

and induction can carry us, the living cell has absolute need of a

vital origin and can never originate by the exclusive agency of the

physicochemical forces native to inorganic matter. If organic life

exists in simpler terms than the cell, science knows nothing of it, and

no observed process, simple or complicated, of inorganic nature, nor

any artificial synthesis of the laboratory, however ingenious, has ever

succeeded in duplicating the wonders of the simplest living cell.

§ 3. Chemical Theories of the Origin of Life

In fact, the very notion of a chemical synthesis of living matter

is founded on a misconception. It would, indeed, be rash to set

limits to the chemist’s power of synthesizing organic compounds, but

living protoplasm is not a single chemical compound. Rather it is

a complex system of compounds, enzymes and organelles, coördinated

and integrated into an organized whole by a persistent principle of

unity and finality. Organic life, to say nothing at all of its unique

dynamics, is a morphological as well as a chemical problem; and,

while it is conceivable that the chemist might synthesize all the

compounds found in dead protoplasm, to reproduce a single detail of

the ultramicroscopic structure of a living cell lies wholly beyond his

power and province. “Long ago,” says Wilson (in the already quoted

address on the “Physical Basis of Life”), “it became perfectly plain

that what we call protoplasm is not chemically a single substance. It

is a mixture of many substances, a mixture in high degree complex, the

seat of varied and incessant transformations, yet one which somehow

holds fast for countless generations to its own specific type. The

evidence from every source demonstrates that the cell is a complex

organism, a microcosm, a living system.” (_Science_, March 9, 1923, p.

278.)

With the chemist, analysis must precede synthesis, and it is only after

a structural formula has been determined by means of quantitative

analysis supplemented by analogy and comparison, that a given compound

can be successfully synthesized. But living protoplasm and its

structures elude such analysis. Intravitous staining is inadequate even

as a means of qualitative analysis, and tests of a more drastic nature

destroy the life and organization, which they seek to analyze. “With

one span,” says Amé Pictet, Professor of Chemistry at the University

of Geneva, “we will now bridge the entire distance separating the

first products of plant assimilation from its final product, namely,

living matter. And it should be understood at the outset that I employ

this term ‘living matter’ only as an abbreviation, and to avoid long

circumlocution. You should not, in reality, attribute life to matter

itself; it has not, it cannot have both living molecules and dead

molecules. Life requires an organization, which is that of cellular

structure, but it remains, in contradistinction to it, outside the

domain of strict chemistry. It is none the less true that the content

of a living cell must differ in its chemical nature from the content of

a dead cell. It is entirely from this point of view that the phenomenon

of life pertains to my subject.... A living cell, both in its chemical

composition and in its morphological structure, is an organism of

extraordinary complexity. The protoplasm that it incloses is a mixture

of very diverse substances. But if there be set aside on the one hand

those substances which are in the process of assimilation and on the

other those which are the by-products of nutrition, and which are in

the process of elimination, there remain the protein or albuminous

substances, and these must be considered, if not the essential factor

of life, at least the theater of its manifestations.... Chemistry,

however, is totally ignorant, or nearly so, of the constitution of

living albumen, for chemical methods of investigation at the very

outset kill the living cell. The slightest rise in temperature,

contact with the solvent, the very powerful effect of even the mildest

reactions cause the transformation that needs to be prevented, and the

chemist has nothing left but dead albumen.” (Smithson. Inst. Rpt. for

1916, pp. 208, 209.)

Chemical analysis associated with physical analysis by means of the

polariscope, spectroscope, x-rays, ultramicroscope, etc. is extremely

useful in determining the structure of inorganic units like the atom

and the molecule. Both, too, throw valuable light on the problem of the

structure of non-living multimolecules such as the crystal units of

crystalloids and the ultramicrons of colloids, but they furnish no clue

to the submicroscopical morphology of the living cell. Such methods do

not enable us to examine anything more than the “physical substrate”

of life, and that, only after it has been radically altered; for it

is not the same after life has flown. At all events, the integrating

principle, the formative determinant, which binds the components of

living protoplasm into a unitary system, which makes of them a single

totality instead of a mere sum or fortuitous aggregate of disparate

and uncoördinated factors, and which gives to them a determinate and

persistent specificity that can hold its own amid a perpetual fluxion

of matter and continual flow of energy, this is forever inaccessible to

the chemist, and constitutes a phenomenon of which the inorganic world

affords no parallel.

With these facts in mind, we can hardly fail to be amused whenever

certain simple chemical reactions obtained _in vitro_ are hailed as

“clue to the origin of life.” When it was found, for instance, that,

under certain conditions, an aldehyde (probably formaldehyde) is

formed in a colloidal solution of chlorophyll in water, if exposed to

sunlight, the discovery gave rise to Bach’s formaldehyde-hypothesis;

for Alexis Bach saw in this reaction “a first step in the origin of

life.” As formaldehyde readily undergoes aldol condensation into

a syrupy fluid called formose, when a dilute aqueous solution of

formaldehyde is saturated with calcium hydroxide and allowed to

stand for several days, there was no difficulty in conceiving the

transition from formaldehyde to the carbohydrates; for formose is a

mixture containing several hexose sugars, and Fischer has succeeded in

isolating therefrom acrose, a simple sugar having the same formula as

glucose, namely: C₆H₁₂O₆. Glyceraldehyde undergoes a similar

condensation. In view of these facts, carbohydrate-production in green

plants was interpreted as a photosynthesis of these substances from

water and carbon dioxide, with chlorophyll acting a sensitizer to

absorb the radiant energy necessary for the reaction. The first step in

the process was thought to be a reduction of carbonic acid to formic

acid and then to formaldehyde, the latter being at once condensed into

glucose, which in turn was supposed to be dehydrated and polymerized

into starch. From the carbohydrates thus formed and the nitrates of the

soil the plant could then synthesize proteins, while oxidation of the

carbohydrates into fatty acids would lead to the formation of fats.

Hence Bach regarded the formation of formaldehyde in the presence of

water, carbon dioxide, chlorophyll, and sunlight as the “first step in

the production of life.” Bateson, however, does not find the suggestion

a very helpful one, and evaluates it at its true worth in the following

contemptuous aside: “We should be greatly helped,” he says, “by

some indication as to whether the origin of life has been single or

multiple.” Modern opinion is, perhaps, inclined to the multiple theory,

but we have no real evidence. Indeed, the problem still stands outside

the range of scientific investigation, and when we hear the spontaneous

formation of formaldehyde mentioned as a possible first step in

the origin of life, we think of Harry Lauder in the character of a

Glasgow schoolboy pulling out his treasures from his pocket—“That’s a

wassher—for makkin’ motor cars.” (“Presidential Address,” cf. Smithson.

Inst. Rpt. for 1915, p. 375.)

Bach, moreover, takes it for granted that the formation of formaldehyde

is really the first step in the synthesis performed by the green plant,

and he claims that formaldehyde is formed when carbon dioxide is passed

through a solution of a salt of uranium in the presence of sunlight.

Fenton makes a similar claim in the case of magnesium, asserting that

traces of formaldehyde are discernible when metallic magnesium is

immersed in water saturated with carbon dioxide. But at present it

begins to look as though the spontaneous formation and condensation of

formaldehyde had nothing to do with the process that actually occurs

in green plants. Certain chemists, while admitting that an aldehyde

is formed when chlorophyll, water, and air are brought together in

the presence of sunlight, deny that the aldehyde in question is

formaldehyde, and they also draw attention to the fact that this

aldehyde may be formed in an atmosphere entirely destitute of carbon

dioxide. In fact, the researches conducted by Willstätter and Stoll,

and later (in 1916) by Jörgensen and Kidd tend to discredit the common

notion that carbohydrate-production in plants is the result of a direct

union of water and carbon dioxide. Botany textbooks still continue to

parrot the traditional view. We cannot any longer, however, be sure but

that the term photosynthesis may be a misnomer.

Carbohydrate-formation in plants seems to be more analogous to

carbohydrate-formation in animals than was formerly thought to be the

case. In animals, as is well known, glycogen or animal starch is formed

not by direct synthesis, but by deämination and reduction of proteins.

In a similar way, it is thought that the production of carbohydrates

in plants may be due to a breaking down of the phytyl ester in

chlorophyll, the chromogen group functioning (under the action of

light) alternately as a dissociating enzyme in the formation of sugars

and a synthesizing enzyme in the reconstruction of chlorophyll. Phytol

is an unsaturated alcohol obtained when chlorophyll is saponified by

means of caustic alkalis. Its formula is C₂₀H₃₉OH, and chlorophyll

consists of a chromogen group containing magnesium (MgN₄C₃₂H₃₀O) united

to a diester of phytyl and methyl alcohols.

Experimental results are at variance with the theory that chlorophyll

acts as a sensitizer in bringing about a reduction of carbonic

acid, after the analogy of eosin, which in the presence of light

accelerates the decomposition of silver salts on photographic plates.

Willstätter found that, when a colloidal solution of the pure extract

of chlorophyll in water is exposed to sunlight and an atmosphere

consisting of carbon dioxide exclusively, no formaldehyde is formed,

but the chlorophyll is changed into yellow phæophytin owing to the

removal of the magnesium from the chromogen group by the action of the

carbonic acid. Jörgensen, on the other hand, discovered that in an

atmosphere of pure oxygen, formaldehyde is formed, apparently by the

splitting off and reduction of the phytyl ester of chlorophyll. Soon,

however, the formaldehyde is oxidized to formic acid, which replaces

the chlorophyllic magnesium with hydrogen, thus causing the green

chlorophyll to degenerate into yellow phæophytin and finally to lose

its color altogether. The dissociation of the chromogen group may be

due to the fact that the reaction takes place _in vitro_, and may not

occur in the living plant. At all events, it would seem that plants,

like animals, manufacture carbohydrates by a destructive rather than a

constructive process, and that water and carbon dioxide serve rather

as materials for the regeneration of chlorophyll than as materials out

of which sugars are directly synthesized.

A new theory has been proposed by Dr. Oskar Baudisch, who seems to

have sensed the irrelevance of the formaldehyde hypothesis, and to

have sought another solution in connection with the chromogen group of

chlorophyll. He finds a more promising starting-point in formaldoxime,

which, he claims, readily unites with such metals as magnesium and iron

and with formaldehyde, in the presence of light containing ultra-violet

rays, to form organic compounds analogous to the chromogen complexes

in chlorophyll and hæmoglobin. Oximes are compounds formed by the

condensation of one molecule of an aldehyde with one molecule of

hydroxylamine (NH₂OH) and the elimination of a molecule of water. Hence

Dr. Baudisch imagines that, given formaldoxime (H₂C:N·OH), magnesium,

and ultra-violet rays, we might expect a spontaneous formation of

chlorophyll leading eventually to the production of organic life. “It

is his theory that life may have been caused through the direct action

of sunlight upon water, air, and carbon dioxide in the ancient geologic

past when, he believes, sunlight was more intense and contained

more ultra-violet light and the air contained more water vapor and

carbon dioxide than at the present time.” (_Science_, April 6, 1923,

Supplement XII.)

This is the old Spencerian evasion, the fatuous appeal to “conditions

unlike those we know,” the unverified and unverifiable assumption

that an unknown past must have been more favorable to spontaneous

generation than the known present. In archæozoic times, the temperature

was higher, the partial pressure of atmospheric carbon dioxide

greater, the percentage of ultra-violet rays in sunlight larger.

Such contentions are interesting, if true, but, for all that, they

may, “like the flowers that bloom in the spring,” have nothing to do

with the case. Nature does not, and the laboratory cannot, reproduce

the conditions which are said to have brought about the spontaneous

generation of formaldoxime and its progressive transmutation into

phycocyanin, chlorophyll and the blue-green algæ. What value, then,

have these conjectures? If it be the function of natural science to

discount actualities in favor of possibilities, to draw arguments from

ignorance, and to accept the absence of disproof as a substitute for

demonstration, then the expedient of invoking the unknown in support

of a speculation is scientifically legitimate. But, if the methods of

science are observation and induction, if it proceeds according to the

principle of the uniformity of nature, and does not utterly belie its

claim of resting upon factual realities rather than the figments of

fancy, then all this hypothecation, which is so flagrantly at variance

with the actual data of experience and the unmistakable trend of

inductive reasoning, is not science at all, but sheer credulity and

superstition.

When we ask by what right men of science presume to lift the veil of

mystery from a remote past, which no one has observed, we are told that

the justification of this procedure is the principle of the uniformity

of nature or the invariability of natural laws. Nature’s laws are the

same yesterday, today, and forever. Hence the scientist, who wishes

to penetrate into the unknown past, has only to “prolong the methods

of nature from the present into the past.” (Tyndall.) If we reject

the soundness of this principle, we automatically cut ourselves off

from all certainty regarding that part of the world’s history which

antecedes human observation. Either nature’s laws change, or they do

not. If they never change, then Spontaneous Generation is quite as

much excluded from the past as it is from the present. If, however, as

Hamann and Fechner explicitly maintain, nature’s laws do change, then,

obviously, no knowledge whatever is possible respecting the past, since

it is solely upon the assumption of the immutable constancy of such

laws that we can venture to reconstruct prehistory.

The puerile notion that the synthesis of organic substances in the

laboratory furnishes a clue to the origin of organic life on earth is

due to a confusion of organic, with living and organized, substances.

It is only in the production of organic substances that the chemist

can vie with the plant or animal. These are lifeless and unorganized

carbon compounds, which are termed organic because they are elaborated

by living organisms as a metaplastic by-product of their metabolism.

Such substances, however, are not to be confounded with animate matter,

_e.g._ a living cell and its organelles, or even with organized matter,

_e.g._ dead protoplasm. These the chemist cannot duplicate; for

vitality and organization, as we have seen, are things that elude both

his analysis and his synthesis. Even with respect to the production of

organic substances, the parallelism between the living cell and the

chemical laboratory is far from being a perfect one. Speaking of the

metaplastic or organic products of cells, Benjamin Moore says: “Most

of these are so complex that they have not yet been synthesized by the

organic chemist; nay, even of those that have been synthesized, it may

be remarked that all proof is wanting that the syntheses have been

carried out in identically the same fashion and by the employment of

the same forms of energy in the case of the cell as in the chemist’s

laboratory. The conditions in the cell are widely different, and at the

temperature of the cell and with such chemical materials as are at hand

in the cell no such organic syntheses have been artificially carried

out by the forms of energy extraneous to living tissue.” (“Recent

Advances in Physiology and Bio-Chemistry,” p. 10.) Be that as it may,

however, the prospect of a laboratory synthesis of an organic substance

like chlorophyll affords no ground whatever for expecting a chemical

synthesis of living matter. The chlorophyllic tail is inadequate to

the task of wagging the dog of organic life. In this connection, Yves

Delage’s sarcastic comment on Schaaffhausen’s theory is worthy of

recall. The latter had suggested (in 1892) that life was initiated by a

chemical reaction, in which water, air, and mineral salts united under

the influence of light and heat to produce a colorless _Protococcus_,

which subsequently acquired chlorophyll and became a _Protococcus

viridis_. “If the affair is so simple,” writes Delage, “why does

not the author produce a few specimens of this _protococcus_ in his

laboratory? We will gladly supply him with the necessary chlorophyll.”

(“La structure du protoplasma et les théories sur l’hérédité,” p. 402.)

Another consideration, which never appears to trouble the visionaries

who propound theories of this sort, is the fact that the inert elements

and blind forces of inorganic nature are, if left to themselves,

utterly impotent to duplicate even so much as the feats of the

chemical laboratory, to say nothing at all of the more wonderful

achievements possible only to living organisms. In the laboratory,

the physicochemical forces of the mineral world are coördinated,

regulated, and directed by the guiding intelligence of the chemist.

In that heterogeneous conglomerate, which we call brute matter, no

such guiding principle exists, and the only possible automatic results

are those which the fortuitous concurrence of blind factors avails to

produce. Chance of this kind may vie with art in the production of

relatively simple combinations or systems, but where the conditions are

as complex as those, which the synthesis of chlorophyll presupposes,

chance is impotent and regulation absolutely imperative. How much more

is this true, when there is question of the production of an effect

so complicatedly telic as the living organism! “I venture to think,”

says Sir William Tilden, in a letter to the London _Times_ (Sept. 10,

1912), “that no chemist will be prepared to suggest a process by which,

from the interaction of such materials (viz., inorganic substances),

anything approaching a substance of the nature of a proteid could be

formed or, if by a complex series of changes a compound of this kind

were conceivably produced, that it would present the characters of

living protoplasm.” In the concluding sentence of his letter, the

great chemist seems to deprecate even the discussion of a chemical

synthesis of living matter, whether spontaneous or artificial. “Far

be it from any man of science,” he says, “to affirm that any given set

of phenomena is not a fit subject of inquiry and that there is any

limit to what may be revealed in answer to systematic and well-directed

investigation. In the present instance, however, it appears to me that

this is not a field for the chemist nor one in which chemistry is

likely to afford any assistance whatever.” In any case, the idea that a

chaos of unassorted elements and undirected forces could succeed where

the skill of the chemist fails is preposterous. No known or conceivable

process, or group of processes, at work in inorganic nature, is equal

to the task. Chance is an explanation only for minds insensible to the

beauty and order of organic life.

Darwin inoculated biological science with this Epicurean metaphysics,

when, in his “Origin of Species,” he ascribed discriminating and

selective powers of great delicacy and precision to the blind factors

of a heterogeneous and variable environment. He compared natural

selection to artificial selection, and in so doing, he was led

astray by a false implication of his own analogy—“I have called this

principle,” he says, “by which each slight variation, if useful, is

preserved, by the term natural selection, in order to mark its relation

to man’s power of selection.” (“Origin of Species,” 6th ed., c. III,

p. 58.) Having likened the unintelligent and fortuitous selection

and elimination exercised by the environment to the intelligent and

purposive selection and elimination practiced by animal breeders and

horticulturists, he pressed the analogy to the unwarranted extent of

attributing to a blind, lifeless, and impersonal aggregate of minerals,

liquids, and gases superhuman powers of discretion. To preserve

even the semblance of parity, he ought first to have expurgated the

process of artificial selection by getting rid of the element of

human intelligence, which lurks therein, and vitiates its parallelism

with the unconscious and purposeless havoc wrought at random by the

blind and uncoördinated agencies of the environment. If inorganic

nature were a vast and multifarious mold, a preformed sieve with

holes of different sizes, a separator for sorting coins of various

denominations, Darwin’s idea would be, in some degree, defensible, but

this would only transfer the problem of cosmic order and intelligence

from the organism to the environment. As a matter of fact, the

mechanism of the environment is far too _simple_ in its structure

and too _general_ in its influence to account for the complexities

and specificities of organisms, that is, for the morphology and

specific differences of plants and animals. Hence the selective work

of the environment is negligible in the positive sense, and consists,

for the most part, in a tendency to eliminate the abnormal and the

subnormal. On the other hand, the environment as well as the organism

is fundamentally teleological, and the environmental mechanism, though

simple and general, is nevertheless expressly preadapted for the

maintenance of organic life. Henderson, the bio-chemist of Harvard, has

shown conclusively, in his “Fitness of the Environment” (1913), that

the environment itself has been expressly selected with this finality

in view, and that the inorganic world, while not the active cause, is,

nevertheless, the preördained complement of organic life.

Simple constructions may, indeed, be due to pure accident as well

as deliberate art, inasmuch as they presuppose but few and easy

conditions. Complex constructions, on the contrary, provided they be

systematic and not chaotic, are not producible by accident, but only

by art, because they require numerous and complicated conditions.

Operating individually, the unconscious factors of inorganic nature

can produce simple and homogeneous constructions such as crystals.

Operating in uncoördinated concurrence with one another, these blind

and unrelated agencies produce complex chaotic formations such as

mountains and islands, mere heterogeneous conglomerates, destitute

of any determinate size, shape, or symmetry, constructions in which

every single item and detail is the result of factors each of

which is independent of the other. In short, the efficacy of the

unconscious and uncoordinated physicochemical factors of inorganic

nature is limited to fortuitous results, which serve no purpose,

embody no intelligible law, convey no meaning nor idea, and afford

no æsthetic satisfaction, being mere aggregates or sums rather than

natural units and real totalities. But it does not extend to the

production of complex systematic formations such as living organisms

or human artefacts. Left to itself, therefore, inorganic nature might

conceivably duplicate the simplest artefacts such as the chipped flints

of the savage, and it might also construct a complex heterogeneous

chaos of driftwood, mud, and sand like the Great Raft of the Red River,

but it would be utterly impotent to construct a complicated telic

system comparable to an animal, a clock, or even an organic compound,

like chlorophyll.

In this connection, it is curious to note how extremely myopic the

scientific materialist can be, when there is question of recognizing

a manifestation of Divine intelligence in the stupendous teleology of

the living organism, and how incredibly lynx-eyed he becomes, when

there is question of detecting evidences of human intelligence in the

eoliths alleged to have been the implements of a “Tertiary Man.” In

the latter case, he is never at a loss to determine the precise degree

of chipping, at which an eolith ceases to be interpretable as the

fortuitous product of unconscious processes, and points infallibly to

the intelligent authorship of man, but he grows strangely obtuse to

the psychic implications of teleology, when it comes to explaining the

symmetry of a starfish or the beauty of a Bird of Paradise.

In conclusion, it is clear that the hypothesis of a spontaneous

origin of organic life from inorganic matter has in its favor neither

factual evidence nor aprioristic probability, but is, on the contrary,

ruled out of court by the whole force of the scientific principle of

induction. To recapitulate, there are no subcellular organisms, and

all cellular organisms (which is the same as saying, all organisms),

be they unicellular or multicellular, originate exclusively by

reproduction, that is, by generation from living parents of the same

organic type or species. This is the law of genetic vital continuity,

which, by the way, Aristotle had formulated long before Harvey, when

he said: “It appears that all living beings come from a germ, and the

germ from parents.” (“De Generatione Animalium,” lib. I, cap. 17.) All

reproduction, however, is reducible to a process of cell-division. That

such is the case with unicellular organisms is evident from the very

definition of a cell. That it is also true of multicellular organisms

can be shown by a review of the various forms of reproduction occurring

among plants and animals.

§ 4. =Reproduction and Rejuvenation=

Reproduction, the sole means by which the torch of life is relayed

from generation to generation, the exclusive process by which

living individuals arise and races are perpetuated, consists in the

separation of a germ from the parent organism as a physical basis for

the development of a new organism. The germ thus separated may be

many-celled or one-celled, as we shall see presently, but the separated

cells, be they one or many, have their common and exclusive source in

the process of mitotic cell-division. In a few cases, this divisional

power or energy of the cell seems to be perennial by virtue of an

inherent inexhaustibility. In most cases, however, it is perennial by

virtue of a restorative process involving nuclear reorganization. In

the former cases, which are exceptional, the cellular stream of life

appears to flow onward forever with steady current, but as a general

rule it ebbs and flows in cycles, which involve a periodic rise

and fall of divisional energy. The phenomena of the life-cycle are

characteristic of most, perhaps all, organisms. The complete life-cycle

consists of three phases or periods, namely: an adolescent period of

high vitality, a mature period of balanced metabolism, and a senescent

period of decline. Each life-cycle begins with the germination of the

new organism and terminates with its death, and it is reproduction

which constitutes the connecting link between one life-cycle and

another.

Reproduction, as previously intimated, is mainly of two kinds, namely:

somatogenic reproduction, which is less general and confined to the

metists, and cytogenic reproduction, which is common to metists and

protists, and which is the ordinary method by which new organisms

originate. Reproduction is termed somatogenic, when the germ separated

from the body of the parent consists of a whole mass of somatic or

tissue cells not expressly set aside and specialized for reproductive

purposes. Reproduction is termed cytogenic, when the germ separated

from the parent or parents consists of a single cell (_e.g._ a spore,

gamete, or zygote) dedicated especially to reproductive purposes.

Cytogenic reproduction may be either nonsexual (agamic) or sexual,

according as the cell which constitutes the germ is an agamete or

a gamete. An agamete is a germ cell not specialized for union with

another complementary cell, or, in other words, it is a reproductive

cell incapable of syngamy, _e.g._ a spore. A gamete, on the other hand,

is a reproductive cell (germ cell) specialized for the production of a

zygote (a synthetic or diploid germ cell) by union with a complementary

cell, _e.g._ an egg, or a sperm.

Nonsexual cytogenic reproduction is of three kinds, according to the

nature of the agamete. When a unicellular organism gives rise to two

new individuals by simple cell-division, we have fissiparation or

binary fission. When a small cell or bud is formed and separated by

division from a larger parent cell, we have budding (gemmation) or

unequal fission. When the nucleus of the parent cell divides many

times to form a number of daughter-nuclei, which then partition the

cytoplasm of the parent cell among themselves so as to form a large

number of reproductive cells called spores, we have what is known

as sporulation or multiple fission. The first and second kind of

nonsexual reproduction are confined to the protists, but the third

kind (sporulation) also occurs among the metists.

Sexual cytogenic reproduction is based upon gametes or mating germ

cells. Since complementary gametes are specialized for union with each

other to form a single synthetic cell, the zygote, the number of their

nuclear threads or chromosomes is reduced to one half (the _haploid

number_) at the time of maturation, so that the somatic or tissue cells

of the parent organism have double the number (the _diploid number_)

of chromosomes present in the reduced or mature gametes. Hence, when

the gametes unite to form a zygote, summation is prevented and the

diploid number of chromosomes characteristic of the given species of

plant or animal is simply restored by the process of syngamy or union.

The process by which the number of chromosomes is reduced in gametes is

called _meiosis_, and, among the metists, it is distinct from syngamy,

which, in their case, is a separate process called fertilization. Among

the protists, we have, besides fertilization, another type of syngamy

called conjugation, which combines meiosis with fertilization.

In sexual reproduction, we have three kinds of gametes, namely:

isogametes, anisogametes, and heterogametes. In the type of sexual

reproduction known as isogamy, the complementary gametes are exactly

alike both in size and shape. There is no division of labor between

them. Each of the fusing gametes is equally fitted for the double

function which they must perform, namely, the kinetic function, which

enables them to reach each other and unite by means of movement,

and the trophic function which consists in laying up a store of

food for the sustenance of the developing embryo. In anisogamy, the

complementary gametes are alike in shape, but unlike in size, and

here we have the beginning of that division of labor, upon which the

difference of gender or sex is based. The larger or female gamete is

called a macrogamete. It is specialized for the trophic rather than

the kinetic function, being rendered more inert by having a large

amount of yolk or nutrient material stored up within it. The smaller

or male gamete is called a microgamete. It is specialized for the

kinetic function, since it contains less yolk and is the more agile of

the two. In anisogamy, however, the division of labor is not complete,

because both functions are still retained by either gamete, albeit

in differing measure. In the heterogamy, the differentiation between

the male and female gametes is complete, and they differ from each

other in structure as well as size. The larger or female gamete has

no motor apparatus and retains only the trophic function. The kinetic

function is sacrificed to the task of storing up a food supply for the

embryo. Such a gamete is called a hypergamete or egg. The smaller or

male gamete is known, in this case, as a hypogamete or sperm. It has a

motor apparatus, but no stored-up nutrients, and has even sloughed off

most of its cytoplasm, in its exclusive specialization for the motor

function. In heterogamy, accordingly, the division of labor is complete.

We may distinguish two principal kinds of sexual reproduction, namely:

unisexual reproduction and bisexual reproduction. When a single gamete

such as an unfertilized egg gives rise (with, or without, chromosomal

reduction) to a new organism, we have unisexual reproduction or

parthenogenesis. Parthenogenesis from a reduced egg gives rise to an

organism having only the haploid number of chromosomes, as is the case

with the drone or male bee, but unreduced eggs give rise to organisms

having the diploid number of chromosomes. Parthenogenesis, as we shall

see presently, can, in some cases, be induced by artificial means.

When reproduction takes place from a zygote or diploid germ cell

formed by the union of two gametes, we have what is known as bisexual

reproduction or syngamy. It is, perhaps, permissible to distinguish a

third or intermediate kind of sexual reproduction, for which we might

coin the term autosexual. What we refer to as autosexual reproduction

is usually known as autogamy, and occurs when a diploid nucleus is

formed in a germ cell by the union (or, we might say, reunion) of

two daughter-nuclei derived from the same mother-nucleus. Autogamy

occurs not only among the protists (_e. g._ _Amœba albida_), but also

among the metists, as is the case with the brine shrimp, _Artemia

salina_, in which the diploid number of chromosomes is restored

after reduction by a reunion of the nucleus of the second polar body

with the reduced nucleus of the egg. Autogamy is somewhat akin to

kleistogamy, which occurs among hermaphroditic metists of both the

plant and animal kingdoms. The violet is a well-known example. In

kleistogamy or self-fertilization, the zygote is formed by the union of

two gametes derived from the same parent organism. Strictly speaking,

however, kleistogamy is not autogamy, but syngamy, and must, therefore,

be classed as bisexual reproduction. It is, of course, necessarily

confined to hermaphrodites.