Transcriber’s notes:
The text of this book has been preserved as in the original except
for correction of some typographic errors (see below) and punctuation
inconsistencies. Italic text is denoted by _underscores_ and a caret
mark ^ precedes any superscripted character(s). Footnotes have been
numbered and positioned below the relevant paragraphs, and some
illustration captions have been moved closer to the relevant text.
Corrected misspellings include the following:
constitutent —> constituent
It —> If
o —> to
endotheliun —> endothelium
ecomomy —> economy
involutary —> involuntary
old factory —> olfactory
tacile —> tactile
irrevelant —> irrelevant
tranverse —> transverse
decebrate —> decerebrate
Thistleton —> Thiselton
opprobious —> opprobrious
Duputryen's —> Dupuytren's
ditēthēsis —> diēthēsis
INITIATIVE IN
EVOLUTION
BY
WALTER KIDD, M.D., F.R.S.E.
AUTHOR OF
“USE--INHERITANCE,” “DIRECTION OF HAIR IN ANIMALS AND MAN,”
“THE SENSE OF TOUCH IN MAMMALS AND BIRDS,” ETC.
_WITH NUMEROUS ILLUSTRATIONS_
H. F. & G. WITHERBY
326 HIGH HOLBORN, LONDON
1920
PREFACE.
The Great War imposed on speculative biology a moratorium as in the
long vacation of lawyers, in which are causes left over to the next
term. And so the old case Lamarck _versus_ Weismann was not heard in
the Courts of Science during the war. In the present term it is due to
be heard afresh, and at some future date to come up for settlement.
The chapters that follow comprise some of the pleadings on behalf of
the plaintiff and are part of the brief of a junior counsel. This
adjective, alas! signifies not the years--for such are often old enough
to be the fathers of the leaders--but the standing and attainments of
a junior. But in the open Court of Science, and on suited occasions,
it may be the business of a junior to question, in the interests of
his client, the authority even of Attorneys-General and Lords Chief
Justice. In matters of thought and inquiry it is useless to retreat
within a stronghold and bar the gates. It may be satisfactory to
himself for one Milner to write a book on behalf of a certain body of
doctrine and call it _The End of Controversy_, but the book should
have held the sub-title _The End of Progress_. The Newtons, Pasteurs
and Darwins have seldom wielded the weapon of controversy, though the
triumph of _The Origin of Species_ would have been slower without the
aid of Darwin’s brilliant champion and candid friend. But, if the
leaders seldom need such help, for the Gibeonite it is a matter of
course and simple necessity. With all the urbanity due to the great
subject-matter should this pleasant duty be performed. Who would not
prefer to the fierce Spaniard the genial Portuguese, discussing all
subjects without rancour, and lover of bull-fights though he be, taking
care to wrap in cork the horns of his fighting bulls?
The earlier chapters treat of the arrangement of the mammalian hair,
which has occupied my attention for over twenty years, and this
has led straight to the other subjects, because of their bearing on
Lamarckism and Initiative in Evolution. The tentative conclusions
reached years ago have been strengthened by further knowledge and
reflection, and perhaps by certain criticisms. The furrow ploughed
may have been lonely, but the pursuit has not been without the mild
pleasure of seeing fresh scattered portions of the field coming into
their natural order. The resulting state of mind resembles that of
a certain Mr. Burke recorded in the annals of a golf club, second
to none, the Ancient, and now Royal Blackheath, among whose minutes
appears the following:--
“20th September, 1834.
Present, Mr. Burke, _Solus_.
The dinner was good, wine abundant, and the utmost harmony prevailed.
The want of grouse was severely felt this day.”
It is written on page 101 of the _Chronicles of Blackheath Golfers_.
My debt to such writings as those of Professors Arthur Keith, Woods
Jones, Graham Kerr, and Professors Sherrington, Starling, Schäfer,
McDougall and Ward is too obvious to the reader to need more than a
bare mention.
I have to thank one critic, Miss Inez Whipple, now Mrs. H. Wilder
Harris, for her able if hostile criticism of two former books of mine
which has been of use in this one; and Mr. R. E. Holding for good help
extending over many years in the preparation of the illustrations, and
for many a good suggestion.
W.K.
CONTENTS.
CHAPTER PAGE
I.--From Known to Unknown 1
II.--Review of the Position 8
III.--The Problems Presented 22
IV.--Initial Variations and Total Experience 30
V.--Method of Proof 36
VI.--Evidence from Arrangement of Hair 39
VII.--The Evolution of Patterns of Hair 50
VIII.--Can Muscular Action change the Direction
of Hair in the Individual? 64
IX.--Habits and Hair of Ungulates 74
X.--Habits and Hair of Ungulates 86
XI.--Habits and Hair of Carnivores 92
XII.--Habits and Hair of Carnivores 98
XIII.--Habits and Hair of Primates 103
XIV.--Miscellaneous Examples 115
XV.--Experimental 124
XVI.--First Summary 140
XVII.--Varieties of Epidermis 145
XVIII.--Arrangement of the Papillary Ridges 157
XIX.--Flexures of the Palm and Sole 170
XX.--The Evolution of a Bursa 178
XXI.--The Plantar Arch 192
XXII.--Muscles 200
XXIII.--Innervation of the Human Skin 218
XXIV.--The Building of Reflex Arcs 231
SUMMARY 257
INDEX 259
LIST OF ILLUSTRATIONS.
FIG. PAGE
1 Arrangement of hair on the forearm 42
2 Diagrams of hair-patterns 51
3, 4, 5 Neck of horse, showing muscles and tendons 53, 54
6–19 Side of neck of various horses, showing
varieties of hair-patterns 56–62
20–29 Illustrations of human eyebrows, showing
muscular action and hair-direction 70–73
30 Front view of horse, showing pectoral pattern 76
31 Side view of horse showing hair-direction 77
32, 32a Frontal region of horses, showing muscles and
hair-pattern 78
33 Side view of horse, showing chief superficial
muscles 79
34, 35 Side and back views of cow, showing
hair-patterns on back 88
36 Lioness, showing direction of hair-streams on
muzzle 93
37 Back of lion, showing hair-pattern 95
38–40 Gluteal region, foreleg and chest of
domestic dog, showing hair-direction 99, 101
41 Arrangement of hair on back of lemur,
chimpanzee and man 105
42 _Idem_ chest 109
43 Giraffe, showing hair-patterns of neck 116
44 Giraffe in attitude of drinking or browsing
off the ground 117
45 Bongo, showing hair-patterns of chest 119
46 Kiang. Side view showing inguinal and
axillary patterns 121
47 Forefoot of llama, showing hair-direction 122
48 Two-toed sloth, showing action of gravity
on hair 123
49 Domestic horse, fully harnessed 128
50 Side view of domestic horse, showing
reversed hair due to harness 129
51–58 Necks of various horses, showing reversed
hair due to collar 132–135
59 Right hand, drawing of papillary ridges,
made from impressions 158
60 Right foot. _Idem_ 160
61–70 Hands and feet of lower animals,
showing papillary ridges 161, 163–166, 168
71 Flexures on palm of right hand.
Drawing made from impression 171
72–79 Flexures on hands and feet of various
lower animals 172–175
80 Drawing of flexures of sole of foot of man,
young adult 176
CHAPTER I.
FROM KNOWN TO UNKNOWN
Upward--still upward--still upward to the highest! Such is the claim
of modern man for the story of himself and the lower inhabitants of
the globe. The zoologists have gone so far as to confer upon him the
surname Sapiens--Homo Sapiens. Learned indeed he is, and heir of all
the ages, but whether or not his assumed surname be warranted the
doctrine of descent with modification can never again be questioned.
The work of Darwin was crowned when he compelled a general acceptance
of that doctrine, and now the Descent of Man and the Ascent of Man
are equivalent terms for a natural process which has converted man
from a thing to a person, and is the foundation of all modern thought.
The biologist works secure in the knowledge that he is studying some
portion of a chain of life stretching back for incalculable ages, and
is not careful to produce those missing links demanded by the once
formidable foes of his fundamental principle. Haeckel may announce that
Pithecanthropus Erectus of Dubois is truly a Pliocene remainder of that
famous group of highest Catarrhines which were the immediate pithecoid
ancestors of man. This may or may not be true, but if true it makes
the descent of man from a lower stock none the surer, the increasing
verification of which is not found to rest on missing links.
Many of the discoveries of modern science are made by proceeding from
known phenomena to the unknown, or, more precisely, from the well-known
through the little-known to the hitherto unknown.
As to the validity of knowledge it is enough to say this--and pass
on--_all our knowledge is provisional and imperfect, and much of our
ignorance is as transient as ourselves_.
There are two chief ways in which historians deal with their
subject-matter, though the moderns combine them. When oral tradition
gives place to written records the lineal descendant of the bards
and annalists collects his scanty authorities and compiles his story
from them from beginning to end. The Anglo-Saxon Chronicle of Bede
and Alfred, the Book of Howth, the works of Giraldus Cambrensis, the
Chronicles of Froissart and the Memoirs of de Comines were composed
in the only way that was then possible. But the muse of history
entered on a deeper and more fruitful course when about ninety years
ago the study of documents became an essential feature of historical
work. It was then that the historian grew up, entered upon his finest
inheritance and assumed his Greek title, Enquirer, Student of facts,
Man of research. He is now nothing if not a man of science as well as
of letters. With a wealth of documents within his reach so great that
the 3239 Vatican cases full of them formed by no means the richest
collection in the archives of Europe, he proceeds to read backwards
correctly what many an earlier annalist read forwards falsely. “We
are still at the beginning of the documentary age which is destined
to make history independent of historians, to develop learning at the
expense of writing, and to accomplish a revolution in other sciences as
well.”[1]
[1] Acton. _A Lecture on the Study of History_, p. 19.
The Historian a Biologist.
It is not too much to say that he who studies history, national,
political, constitutional, ecclesiastical, military or economic is as
much a biologist in the widest sense as the botanist and zoologist.
Indeed these were till recently termed students of natural _history_,
until the advance of knowledge gave us the various special groups of
workers, conveniently called biologists. Though the study of human
history by documents is an essential part of the historical method
and the student may read _his_ subject backwards, this would not of
itself warrant the technical biologist in doing so, even though he be
a child of Nature and part of her--“Nature’s insurgent son.” But some
reflection on the facts of certain provinces of science affords ample
justification for the method. It is chiefly in questions of origin
that it avails, while it fails in that form of research by experiment
which is the glory of modern science. A few examples of the process of
passing from the known to the unknown will illustrate the method.
Darwin.
Much of the _Origin of Species_ and all of the _Descent of Man_ was
founded on this method; thus in the former the conceptions of struggle
took their main rise from the work of Malthus on Human Population, and
of variation from domesticated animals and plants, and this is true
also of Wallace. A mere glance at the divisions of _The Descent of Man_
shows that it could never have been attempted in any other than the
backward way.
Geology.
In their researches on the crust of the earth Playfair, Hutton and
Lyell did not pursue them by going down a coal mine till they came to
the lowest available beds and work upward from these to the highest.
Though for purposes of exposition a great geologist, as Sir Archibald
Geikie, may expound the making of the earth from the lowest to the
highest levels, and Professor Bonney tell us the _Story of our Planet_
from beginning to end as if he had watched it unfolding, Lyell in his
_Principles of Geology_ shows how the studies of his great province
began. There we have the backward reading of its story pursued by
himself and other great ones, and where it led them. Commencing with
the Pleistocene period and passing through Neocene and Eocene periods
through the Mesozoic Era and its cretaceous, jurassic and triassic
systems to the Newer Palæozoic Era and its Permian, carboniferous, and
Devonian systems, the older Palæozoic Era and its Silurian Ordovician
and Cambrian systems, he reaches the unknown. But before all this
patient research and its record is reached he treats, as he must, of
consolidation and alteration of strata, of petrification of organic
remains, elevation of strata, horizontal and inclined stratification,
of faulting, denudation, upheaval and subsidence as they combine
to remodel the earth’s crust. The title of his classical work is
significant--_An Attempt to Explain the Former Changes of the Earth’s
Surface by Reference to Causes now in Operation_ (it may be noted that
in 1830 they were fond of capital letters and of underlining their
words). If these great men had been condemned to the sole use of the
method of the annalist in his treatment of human history, that of the
coal mine in geology, this great province of knowledge would never have
been what it is to-day.
At this point I think it well to state that this illuminating principle
of Lyell is pursued in nearly all the matters of fact and their
interpretation contained in the following chapters, so that from time
to time I shall have to employ the verb, coined for the purpose, when I
attempt to “Lyell” them on behalf of Lamarck.
Anthropology.
The anthropologist could hardly make a start with his research, if,
knowing nothing of his own anatomy, physiology, customs and beliefs, he
tried to interpret the physical features, habits, manners, customs and
rites of an African tribe. Without such prior knowledge he would find
it a profitless task to journey to the banks of the Zambesi and bring
back any intelligible history of the aborigines. If he did not know the
games of a European child how could he understand the variants of them
such as the writer of _Savage Childhood_[2] expounds so well?
[2] _Savage Childhood_, Dudley Kidd.
The Sources of Rivers.
To trace the course and source of a river is a simple task through the
work of modern geographers, and such a pursuit illustrates well the
two methods here considered, but it is doubtful if any river was ever
traced originally from its fountain head to its mouth. The backward
way of such exploration, from the nature of the case, has always been
taken, and men have traced the more or less finished products of the
lower stretches, backward, still backwards, even as in the Indus, to
the still-unknown. The earliest thinkers and seekers in the plains of
Bengal were familiar with much of their great sacred and composite
river as it flowed into its delta. Slowly, laboriously, here a little
and there a little, they learned its stupendous story. They found the
plateau of Tibet in the Himalayas where the twin-sisters, Brahmaputra
and Ganges were born, and saw how from the one high cradle they parted
on their eastward course for a thousand miles with the mountain-chain
between them, and how, coming together again, the one descending
through Assam and the other flowing through the plains, reinforced by
the Jumna, they united to form the Ganges-Brahmaputra. A great subject
indeed for the early geographer, but one which he could only follow in
the backward way. Again how well known and revered in Egypt was the
Nile for thousands of years before its source in Victoria Nyanza could
be traced, even though Nero might send his explorers as far as the
marshes of the White Nile, and Ptolemy’s search for it might lead him
to guess the riddle, and assign it to two great lakes!
Genealogy.
Not many of us can trace our ancestry in the direct male line to
the 8th century by authentic and written documents as did a Hebrew
friend of mine, thus effectually meeting the doubts of a prospective
brother-in-law who asked him as to his fitness to enter a family which
was able to produce a stray peer of the realm in its roll. On the other
hand a man who has lost his parents in childhood may know nothing of
them but that his father’s name was A. Mann, and that he was buried
in a Kentish churchyard. He may go on a pilgrimage and find there
recorded the fact that A. Mann was the son of A. Mann, Gent, who came
from Northumberland. He will doubtless make another pilgrimage and find
there a large vault, and over it an imposing record of many a Mann,
and yet further he may go, and from the Heralds’ College find out the
still earlier derivation of his ancestors.
Detection of a Crime.
There are two chief ways of detecting a crime. By oral evidence from
eye-witnesses or confession of the accused you may get direct proof,
though even here are pitfalls from careless and hasty witnesses on the
one hand, or on the other from a strange perversion of mind of the
confessing person which is well enough known to forensic medicine.
You may thus bring home to the accused his guilt by the method of
the annalist. Or you may employ the more common method of studying
circumstantial evidence; the story of the crime is read backwards and
a verdict of guilty is given. This is the main stuff of which the
prevalent detective story is composed.
A Parable.
A plain parable may well conclude this chapter.
As I mused on the chain of life I found a piece of whipcord which had
been lying by for twenty-five years since some of it was used for
rigging a model yacht, and this very efficient product of human art
seemed to speak to me on the subject of my musings. Perhaps if Huxley
could extract from a piece of chalk or lumps of coal two magnificent
expositions on geology and biology, this little trifle of cord might
afford a text on a way of looking at living things which should be
useful in this old case of Lamarck _v._ Weismann--and others.
Should I learn the story of the whipcord forwards like an annalist,
or backward like a modern historian? Clearly it could be done in a
measure by either method. Here was a highly finished product of which
either might furnish the story, and of which, we may suppose, I knew
nothing. I tried the backward way, and by the aid of a needle began
to unravel it. The cord was as good as if just made, slender, strong,
twisted, with some glazing on the twisted threads. It showed three
main bundles, and each of these was composed of two smaller ones.
The substance of all these six was found when examined with a lens
to consist of minute silky fibres varying from a quarter of an inch
to an inch in length. This was all I could learn without a stronger
magnifying power or a chemical analysis, and the direct search was at
an end. I gathered since then that the first three bundles were called
“strands,” and the two composing each of these “yarns,” and that the
fibres were from a plant called hemp. This did not carry the story
deep or far, and illustrates how often in the backward method facts
have to be supplemented by inference. But I had learnt some undoubted
facts and some inferences from them nearly as certain. Some mind of
man had conceived and hands carried out the division of the bundles of
fibres into three strands, had twisted them somehow so as to reduce
their length by a quarter and yet not far enough to rupture them, and
had thus fitted them the better for their purpose by a reinforcement
of tensile strength due to the twisting. I could also see that this
same mind had seen it better to divide each of these strands into two
yarns before the final twisting, and that in framing the yarns the
silky fibres of the plant had been squeezed together by some powerful
agency and yet not disintegrated, and that the finished product had
been immersed in a protective substance which gave it a slight glaze.
In short, I, though a child in these matters, read much of the story
of this cord in terms of mind dealing with given organic matter. I may
add that I did not imagine myself a little Paley, and that I do not
intend to “take in” the reader as to the argument from design and final
causes, even though this parable may feebly resemble Paley’s study of
a watch. The conclusion was perfectly clear that certain directing
grey cells of a certain brain had interfered with and acted upon some
plastic vegetable matter, and one could at the “strand” stage, the
“yarn” stage, and the “fibre” stage see mind writ large.
The Forward Way.
The limits of the former method are obvious, but I might also attempt
to follow the little story as a crime is followed and described by
eye-witnesses. So I go to an old-fashioned rope-factory and ask the
foreman questions about the making of twine, cords, ropes and cables.
He shows me bundles of hemp; he calls them Russian, Italian or
American, and goes on to tell me how the fibre is “heckled” or combed,
how “tow” is separated from “line,” and how the yarns are pressed
together and twisted, how they are at first rough and bristly, and are
then dressed, polished, and “sized” with such a starch as that of the
potato. When I proceed to ask him about the plant itself his interest
flags, and he becomes vague. He says, “You had better ask the Head,
young Mr. X., he knows these things better.” I find the Head with his
golf clubs over his shoulder and about to start on his “business,” and
he is polite, but says he knows very little about the origin of his
hemp. “You should go over the way and ask Messrs. Y. if they will let
you see the expert who advises them in their business, he will know.”
The expert is at home and kindly and fully describes to me the early
home of the wild _Cannabis Sativa_ in a moderate climate of Asia, the
rich soil it needs for its growth and the various countries of the
world into which it has been introduced; and the bast-fibres of the
bark of this plant which from remote antiquity has supplied the silky
stuff. He then tells me how the stems are dried and crushed, and then
of the important stage of fermentation or “retting” in water, how they
are again beaten in a “break,” then rubbed and “scutched,” and finally
“heckled” or combed; and, as to analytic chemistry, he tells me that
the chief constituent is cellulose. This quest is now over and I know
much I could not find out by the backward method, though the dependence
of its rival upon the presence of honest and capable eye-witnesses
is not less obvious. It is not alone in ecclesiastical history that
cheats and forgers of documents exist. In the world of Nature there
may be, for all we know, biological False Decretals that may lead
us far astray, such perhaps as Amphioxous and Archæopteryx, and the
Pseudo-Isidore who produced them may yet be discovered.