fossiliferous formations of Scotland, our author extended his inquiries
into the mainland of Orkney, and resided for some time in the vicinity
of the busy seaport town of Stromness, as a central point from which the
structure of the Orkney group of islands could be most advantageously
studied. Like that of Caithness, the geology of these islands owes its
principal interest to the immense development of the Lower Old Red
Sandstone formation, and to the singular abundance of its vertebrate
fossils. Though the Orkneys contain only the _third_ part of the Old
Red Sandstone, which, but a few years ago, was supposed to be the least
productive in fossils of any of the geological formations, yet it
furnishes, according to Mr. Miller, more fossil fish than _every_ other
geological system in England, Scotland, and Wales, from the Coal Measures
to the Chalk, inclusive. It is, in short, “_the land of fish_,” and
“could supply with ichthyolites, by the ton and by the ship-load, the
museums of the world.” Its various deposits, with the curious organisms
which they inclose, have been upheaved from their original position
against a granitic axis, about six miles long and one broad, “forming the
great back-bone of the western district of the Island Pomona; and on this
granitic axis, fast jambed in between a steep hill and the sea, stands
the town of Stromness.”
The mass or pile of strata thus uplifted is described by Mr. Miller as a
three-barred pyramid resting on its granite base, exhibiting three broad
tiers—red, black, and gray—sculptured with the hieroglyphics in which
its history is recorded. The great conglomerate base on which it rests,
covering from 10,000 to 15,000 square miles, from the depth of from 100
to 400 feet, consists of rough sand and water-worn pebbles; and above
this have been deposited successive strata of mud, equal in height to
the highest of our mountains, now containing the remains of millions and
tens of millions of fish which had perished in some sudden and mysterious
catastrophe.
In the examination of the different beds of the three-barred formation,
our author discovered a well-marked bone, like a petrified large roofing
nail, in a grayish-colored layer of hard flag, about 100 yards over the
granite, and about 160 feet over the upper stratum of the conglomerate.
This singular bone, which Mr. Miller has represented in a figure, was
probably the oldest vertebrate organism yet discovered in Orkney. It was
5⅞ inches long, 2¼ inches across the head, and ³⁄₁₀ths of an inch thick
in the stem, and formed a characteristic feature of the Asterolepis, as
yet the most gigantic of the ganoid fishes, and probably one of the first
of the Old Red Sandstone. In his former researches, our author had found
that all of the many hundred ichthyolites which he had disinterred from
the Lower Old Red Sandstone were comparatively of a small size, while
those in the Upper Old Red were of great bulk; and hence he had naturally
inferred, that vertebrate life had increased towards the close of the
system—that, in short, it began with an age of dwarfs, and ended with an
age of giants; but he had thus greatly erred, like the supporters of the
development system, in founding positive conclusions on merely negative
evidence; for here, at the very base of the system, where no dwarfs were
to be found, he had discovered one of the most colossal of its giants.
After this most important discovery, Mr. Miller extended his inquiries
easterly for several miles along the bare and unwooded Lake of Stennis,
about fourteen miles in circumference, and divided into an upper arm
lower sheet of water by two long promontories jutting out from each side
and nearly meeting in the middle. The sea enters this lake through the
openings of a long rustic bridge, and hence the lower division of the
lake “is salt in its nether reaches, and brackish in its upper ones;
while the higher division is merely brackish in its nether reaches, and
fresh enough in its upper ones to be potable.” The fauna and flora of
the lake are therefore of a mixed character, the marine and fresh water
animals having each their own reaches, though each kind makes certain
encroachments on the province of the other.
In the marine and lacustrine floras of the lake, Mr. Miller observed
changes still more palpable. At the entrance of the sea, the _Fucus
nodosus_ and _Fucus vesiculosus_ flourish in their proper form and
magnitude. A little farther on in the lake, the F. nodosus disappears,
and the F. vesiculosus, though continuing to exist for mile after mile,
grows dwarfish and stunted, and finally disappears, giving place to
rushes and other aquatic grasses, till the lacustrine has entirely
displaced the marine flora. From these two important facts, the existence
of the fragment of _Asterolepis_ in the lower flagstones of the Orkneys,
and of the “curiously mixed semi-marine semi-lacustrine vegetation in the
Loch of Stennis,” which our author regards as bearing directly on the
development hypothesis, he takes occasion to submit that hypothesis to a
severe examination, and to point out its consequences—its incompatibility
with the great truths of morality and revealed religion. According
to Professor Oken, one of the ablest supporters of the development
theory, “There are two kinds of generation in the world, the creation
proper, and the propagation that is sequent thereon, or the _original
and secondary generation_. Consequently, no organism has been created
of larger size than an infusorial point. No organism is, or ever has
been created, which is not microscopic. Whatever is large has not been
created, but developed. Man has not been created, but developed.” Hence
it follows that during the great geological period, when race after race
was destroyed, and new forms of life called into being, “nature had been
pregnant with the human race,” and that immortal and intellectual Man is
but the development of the Brute—itself the development of some monad or
mollusc, which has been smitten into life by the action of electricity
upon a portion of gelatinous matter.
If the development theory be true, “the early fossils ought to be very
small in size,” and “very low in organization.” In the earliest strata we
ought to find only “mere _embryos_ and _fœtuses_; and if we find instead
the _full-grown_ and _mature_, then must we hold that the testimony of
geology is not only _not in accordance_ with the theory, but in positive
opposition to it.” Having laid this down as the _principle_ by which
the question is to be decided, our author proceeds to consider “what
are the _facts_.” The _Asterolepis_ of Stromness _seems_ to be the
oldest organism yet discovered in the most ancient geological system of
Scotland, in which vertebrate remains occur. It is probably the oldest
Cœlacanth that the world has yet produced, for there is no certain trace
of this family in the great Silurian system, which lies underneath, and
on which, according to our existing knowledge, organic existence first
began. “How, then,” asks Mr. Miller, “on the two relevant points—bulk and
organization—does it answer to the demands of the development hypothesis?
Was it a mere fœtus of the finny tribe, of minute size and imperfect
embryonic faculty? Or was it of, at least, the ordinary bulk, and, for
its class, of the average organization?”
In order to answer these questions, Mr. Miller proceeds in his _third_
chapter to give the recent history of the Asterolepis; in his _fourth_,
to ascertain the cerebral development of the earlier vertebrata; and in
his _fifth_ chapter to describe the structure, bulk, and aspect of the
Asterolepis. In the rocks of Russia certain fossil remains had been long
ago discovered, of such a singular nature as to have perplexed Lamarck
and other naturalists. Their true place among fishes was subsequently
ascertained by M. Eichwald, a living naturalist; and Sir Roderick
Murchison found that they were Ichthyolites of the Old Red Sandstone.
Agassiz gave them the name of _Chelonichthys_; but in consequence of very
fine specimens having been found in the Old Red Sandstone of Russia,
which Professor Asmus of Dorpat sent to the British Museum, and which
exhibited star-like markings, he abandoned his name of _Chelonichthys_,
and adopted that of _Asterolepis_, or star-scale, which Eichwald had
proposed. Many points, however, respecting this curious fossil remained
to be determined, and it was fortunate for science that Mr. Miller was
enabled to accomplish this object by means of a variety of excellent
specimens which he received from Mr. Robert Dick, “an intelligent
tradesman of Thurso, one of those working men of Scotland, of active
curiosity and well developed intellect, that give character and standing
to the rest.” Agassiz had inferred, from very imperfect fragments, that
the _Asterolepis_ was a strongly-helmed fish of the _Cœlacanths_, or
hollow spine family—that it was probably a flat-headed animal, and that
the discovery of a head or of a jaw might prove that the genus Dendrodus
did not differ from it. All these conjectures were completely confirmed
by Mr. Miller, after a careful examination of the specimens of Mr. Dick.
Before proceeding to describe the structure of the gigantic Asterolepis,
Mr. Miller devotes a long and elaborate chapter to the subject of the
cerebral development of the earlier vertebrata, in order to ascertain
in what manner their true brains were lodged, and to discover the
modification which the cranium, as their protecting box, received in
subsequent periods. This inquiry, which he has conducted with great skill
and ability, is not only highly interesting in itself, but will be found
to have a direct bearing on the great question which it is his object to
discuss and decide.
The facts and reasonings contained in this chapter will, we doubt not,
shake to its very base the bold theory of Professor Oken, which has been
so generally received abroad, and which is beginning to find supporters
even among the solid thinkers of our own country. In the _Isis_ of 1818,
Professor Lorenz Oken has given the following account of the hypothesis
to which we allude. “In August, 1806,” says he, “I made a journey over
the Hartz. I slid down through the wood on the south side, and straight
before me, at my very feet, lay a most beautiful blanched skull of
a hind. I picked it up, turned it round, regarded it intensely;—the
thing was done. ‘It is a vertebral column,’ struck me like a flood of
lightning, ‘to the marrow and bone;’ and since that time the skull has
been regarded as a vertebral column.”
This remarkable hypothesis was at first received with enthusiasm by the
naturalists of Germany, and, among others, by Agassiz, who, from grounds
not of a geological kind, has more recently rejected it. It has been
adopted by our distinguished countryman, Professor Owen, and forms the
central idea in his lately published and ingenious work “On the Nature
of Limbs.” The conclusion at which he arrives, that the fore-limbs of
the vertebrata are the ribs of the occipital bone or vertebra set free,
and (in all the vertebrata higher in the scale than the ordinary fishes)
carried down along the vertebral column by a sort of natural dislocation,
is a deduction from the idea that startled Professor Oken in the forest
of the Hartz. Whatever support this hypothesis might have expected from
Geology, has been struck from beneath it by this remarkable chapter of
Mr. Miller’s work; and though anatomists may for a while maintain it
under the influence of so high an authority as Professor Owen, we are
much mistaken if it ever forms a part of the creed of the geologist.
Mr. Miller indeed has, by a most skilful examination of the heads of
the earliest vertebrata known to geologists, proved that the hypothesis
derives no support from the structure which they exhibit, and Agassiz has
even upon general principles rejected it as untenable.
Mr. Miller’s next chapter on the structure, bulk, and aspect of the
Asterolepis, is, like that which precedes it, the work of a master,
evincing the highest powers of observation and analysis. Its size in the
larger specimens must have been very great; and from a comparison of the
proportion of the head in the Ganoids to the length of the body, which
is sometimes as one to five, or one to six, or one to six and a half,
or even one to seven, our author concludes that the total length of the
specimens in his possession must have been at least eight feet three
inches, or from nine feet nine to nine feet ten inches. The remains of an
Asterolepis found by Mr. Dick at Thurso, indicate a length of from twelve
feet five to thirteen feet eight inches; and one of the Russian specimens
of Professor Asmus must have been from _eighteen_ to _twenty-three_ feet
long. “Hence,” says Mr. Miller, “in the not unimportant circumstance
of size—the most ancient Cœlacanths yet known, instead of taking their
places agreeably to the demands of the development hypothesis among the
sprats, sticklebacks, and minnows of their class, took their place among
its huge basking sharks, gigantic sturgeons, and bulky swordfishes.
They were giants, not dwarfs.” Again, judging by the analogies which
its structure exhibits to that of fishes of the existing period, the
Asterolepis must have been a fish high in the scale of organization.
A specimen of Asterolepis, discovered by Mr. Dick, among the Thurso
rocks, and sent to Mr. Miller, exhibited the singular phenomenon of a
quantity of thick tar lying beneath it, which stuck to the fingers when
lifting the pieces of rock. “What had been once the nerves, muscles, and
blood of this ancient Ganoid, still lay under its bones,” a phenomenon
which our author had previously seen beneath the body of a poor suicide,
whose grave in a sandy bank had been laid open by the encroachments of a
river, the sand beneath it having been “consolidated into a dark colored
pitchy mass,” extending a full yard beneath the body. In like manner,
the animal juices of the Asterolepis had preserved its remains, by “the
pervading bitumen, greatly more conservative in its effects than the oil
and gum of an old Egyptian undertaker.” The bones, though black as pitch
retained to a considerable degree the peculiar qualities of the original
substance, in the same manner as the adipocire of wet burying-grounds
preserves fresh and green the bones which it encloses.
In support of his anti-development views, Mr. Miller devotes his next and
_sixth_ chapter to the recent history, order, and size of the fishes of
the Upper and Lower Silurian rocks. Of these ancient formations, the bone
bed of the Upper Ludlow rocks is the only one which, besides defensive
spines of fish, contains teeth, fragments of jaws, and shagreen points,
whereas, in the inferior deposits, defensive spates alone are found. The
species discovered by Professor Phillips, in the Wenlock shale, were
microscopic; and the author of the _Vestiges_ took advantage of this
insulated fact to support his views, by pronouncing the little creatures
to which the species belonged as the fœtal embryos of their class. Mr.
Miller has, however, even on this ground, defeated his opponent. By
comparing the defensive spines of the _Onchus Murchisoni_ of the Upper
Ludlow bed with those of a recent _Spinax Acanthias_, or dog-fish, and
of the _Cestracion Phillippi_, or Port Jackson shark, he arrives at the
conclusion, that the fishes to which the species belonged must be all of
considerable size; and in the following chapter _on the high standing
of the Placoids_ he shews that the same early fishes were high in
intelligence and organization.
In his _ninth_ chapter on the _History and Progress of Degradation_,
our author enters upon a new and interesting subject. The object of
it is to determine the proper ground on which the standing of the
earlier vertebrata should be decided, namely, the test of what he terms
homological symmetry of organization. In nature there are monster
families, just as there are in families monster individuals—men without
feet, hands, or eyes, or with them in a wrong place—sheep with legs
growing from their necks, ducklings with wings on their haunches, and
dogs and cats with more legs than they require. We have thus, according
to our author—1, _monstrosity through defect of parts_; 2, _monstrosity
through redundancy of parts_; and 3, _monstrosity through displacement of
parts_. This last species, united in some cases with the other two, our
author finds curiously exemplified in the geological history of the fish,
which he considers better known than that of any other division of the
vertebrata; and he is convinced that it is from a survey of the progress
of degradation in the great Ichthyic division that the standing of the
kingly fishes of the earlier periods is to be determined.
In the earliest vertebrate period, namely, the Silurian, our author
shews that the fishes were homologically symmetrical in their
organization, as exhibited in the Placoids. In the second great Ichthyic
period, that of the Old Red Sandstone, he finds the first example in
the class of fishes of _monstrosity, by displacement of parts_. In all
the Ganoids of the period, there is the same departure from symmetry
as would take place in man if his neck was annihilated, and the arms
stuck to the back of the head. In the _Coccosteus_ and _Pterichthys_
of the same period, he finds the first example of _degradation through
defect_, the former resembling a human monster without hands, and the
latter one without feet. After ages and centuries have passed away,
and then after the termination of the Palæozoic period, a change takes
place in the formation of the fish tail. “Other ages and centuries pass
away, during which the reptile class attains to its fullest development
in point of size, organization, and number; and then, after the times
of the cretaceous deposits have begun, we find yet another remarkable
monstrosity of displacement introduced among all the fishes of one very
numerous order, and among no inconsiderable proportion of the fishes
of another. In the newly-introduced Ctenoids (_Acanthopterygii_,) and
in those families of the Cycloids which Cuvier erected into the order
_Malacopterygii sub-brachiati_, the hinder limbs are brought forward and
stuck on to the base of the previously misplaced fore limbs. All the
four limbs, by a strange monstrosity of displacement, are crowded into
the place of the extinguished neck. And such, in the present day, is the
prevalent type among fishes. Monstrosity through _defect_ is also found
to increase; so that the snake-like _apoda_, or feet-wanting fishes,
form a numerous order, some of whose genera are devoid, as in the common
eels and the congers, of only the hinder limbs, while in others, as in
the genera _Muræna_ and _Synbranchus_, both hinder and fore-limbs are
wanting.” From these and other facts, our author concludes that as in
existing fishes we find many more proofs of the monstrosity, both from
displacement and defect of parts, than in all the other three classes
of the vertebrata, and as these monstrosities did not appear early, but
late, “the progress of the race as a whole, though it still retains
not a few of the higher forms, has been a progress not of development
from the low to the high, but of degradation from the high to the low.”
An extreme example of the degradation of distortion, superadded to
that of displacement, may be seen in the flounder, plaice, halibut, or
turbot,—fishes of a family of which there is no trace in the earlier
periods. The creature is twisted half round and laid on its side. The
tail, too, is horizontal. Half the features of its head are twisted to
one side, and the other half to the other, while its wry mouth is in
keeping with its squint eyes. One jaw is straight, and the other like
a bow; and while one contains from _four_ to _six_ teeth, the other
contains from _thirty_ to _thirty-five_.
Aided by facts like these, an ingenious theorist might, as our author
remarks, “get up as unexceptionable a theory of degradation as of
development.” But however this may be, the principle of degradation
actually exists, and “the history of its progress in creation bears
directly against the assumption that the earlier vertebrata were of a
lower type than the vertebrata of the same Ichthyic class which exist
now.”
In his next and _tenth_ chapter, our author controverts with his usual
power the argument in favor of the development hypothesis, drawn from
the predominance of the Brachiopods among the Silurian Molluscs. The
existence of the highly organized Cephalopods, in the same formation,
not only neutralizes this argument, but authorizes the conclusion that
an animal of a very high order of organization existed in the earliest
formation. It is of no consequence whether the Cephalopods, or the
Brachiopods were most numerous. Had there been only one cuttle fish in
the Silurian seas, and a million of Brachiopods, the fact would equally
have overturned the development system.
In the same chapter, Mr. Miller treats of the geological history of
the Fossil flora, which has been pressed into the service of the
development hypothesis. On the authority of Adolphe Brongniart, it was
maintained that, previous to the age of the Lias, “Nature had failed to
achieve a tree—and that the rich vegetation of the Coal Measures had
been exclusively composed of magnificent immaturities of the vegetable
kingdom, of gigantic ferns and club mosses, that attained to the size
of forest trees, and of thickets of the swamp-loving horse-tail family
of plants.” True exogenous trees, however, do exist of vast size, and
in great numbers, in all the coal-fields of our own country, as has
been proved by Mr. Miller. Nay, he himself discovered in the Old Red
Sandstone, _Lignite_, which is proved to have formed part of a true
gymnospermous tree, represented by the pines of Europe and America, or
more probably, as Mr. Miller believes, by the Araucarians of Chili and
New Zealand. This important discovery is pregnant with instruction. The
ancient Conifer must have waved its green foliage over dry land, and it
is not probable that it was the only tree in the primeval forest. “The
ship carpenter,” as our author observes, “might have hopefully taken
axe in hand to explore the woods for some such stately pine as the one
described by Milton,—
‘Hewn on Norwegian hills, to be the mast
Of some great admiral.’”
Viewing this _olive leaf_ of the Old Red Sandstone as not at all devoid
of poetry, our author invites us to a voyage from the latest formation up
to the first zone of the Silurian formation,—thus passing from ancient to
still more ancient scenes of being, and finding, as at the commencement
of our voyage, a graceful intermixture of land and water, continent,
river, and sea.
But though the existence of a true Placoid, a real vertebrated fish, in
the Cambrian limestone of Bala, and of true wood at the base of the Old
Red Sandstone, are utterly incompatible with the development hypothesis,
its supporters, thus driven to the wall, may take shelter under the
vague and unquestioned truth that the lower plants and animals preceded
the higher, and that the order of creation was fish, reptiles, birds,
mammalia, quadrumana, and man. From this resource, too, our author
has cut off his opponents, and proceeds to show that such an order of
creation, “at once wonderful and beautiful,” does not afford even the
slightest presumption in favor of the hypothesis which it is adduced to
support.