|Henry Smith Williams|
||Tome III||Tome IV|
Theories of organic evolution
|While the names
of Darwin and Goethe, and in particular that of Lamarck, must always stand
out in high relief in this generation as the exponents of the idea of transmutation
of species, there are a few others which must not be altogether overlooked
in this connection. Of these the most conspicuous is that of Gottfried
Reinhold Treviranus, a German naturalist physician, professor of mathematics
in the lyceum at Bremen.
It was an interesting coincidence that Treviranus should have published the first volume of his Biologie, oder Philosophie der lebenden Natur, in which his views on the transmutation of species were expounded, in 1802, the same twelvemonth in which Lamarck's first exposition of the same doctrine appeared in his Recherches sur l'Organisation des Corps Vivants. It is singular, too, that Lamarck, in his Hydrogelogie of the same date, should independently have suggested "biology" as an appropriate word to express the general science of living things. It is significant of the tendency of thought of the time that the need of such a unifying word should have presented itself simultaneously to independent thinkers in different countries.
That same memorable year, Lorenz Oken, another philosophical naturalist, professor in the University of Zurich, published the preliminary outlines of his Philosophie der Natur, which, as developed through later publications, outlined a theory of spontaneous generation and of evolution of species. Thus it appears that this idea was germinating in the minds of several of the ablest men of the time during the first decade of our century. But the singular result of their various explications was to give sudden check to that undercurrent of thought which for some time had been setting towards this conception. As soon as it was made clear whither the concession that animals may be changed by their environment must logically trend, the recoil from the idea was instantaneous and fervid. Then for a generation Cuvier was almost absolutely dominant, and his verdict was generally considered final.
There was, indeed, one naturalist of authority in France who had the hardihood to stand out against Cuvier and his school, and who was in a position to gain a hearing, though by no means to divide the following. This was Etienne Geoffroy Saint-Hilaire, the famous author of the Philosophie Anatomique, and for many years the colleague of Lamarck at the Jardin des Plantes. Like Goethe, Geoffroy was pre-eminently an anatomist, and, like the great German, he had early been impressed with the resemblances between the analogous organs of different classes of beings. He conceived the idea that an absolute unity of type prevails throughout organic nature as regards each set of organs. Out of this idea grew his gradually formed belief that similarity of structure might imply identity of origin - that, in short, one species of animal might have developed from another.
Geoffroy's grasp of this idea of transmutation was by no means so complete as that of Lamarck, and he seems never to have fully determined in his own mind just what might be the limits of such development of species. Certainly he nowhere includes all organic creatures in one line of descent, as Lamarck had done; nevertheless, he held tenaciously to the truth as he saw it, in open opposition to Cuvier, with whom he held a memorable debate at the Academy of Sciences in 1830 - the debate which so aroused the interest and enthusiasm of Goethe, but which, in the opinion of nearly every one else, resulted in crushing defeat for Geoffrey, and brilliant, seemingly final, victory for the advocate of special creation and the fixity of species.
With that all ardent controversy over the subject seemed to end, and for just a quarter of a century to come there was published but a single argument for transmutation of species which attracted any general attention whatever. This oasis in a desert generation was a little book called Vestiges of the Natural History of Creation, which appeared anonymously in England in 1844, and which passed through numerous editions, and was the subject of no end of abusive and derisive comment. This book, the authorship of which remained for forty years a secret, is now conceded to have been the work of Robert Chambers, the well-known English author and publisher. The book itself is remarkable as being an avowed and unequivocal exposition of a general doctrine of evolution, its view being as radical and comprehensive as that of Lamarck himself. But it was a resume of earlier efforts rather than a new departure, to say nothing of its technical shortcomings, which may best be illustrated by a quotation.
"The whole question," says Chambers, "stands thus: For the theory of universal order - that is, order as presiding in both the origin and administration of the world - we have the testimony of a vast number of facts in nature, and this one in addition - that whatever is left from the domain of ignorance, and made undoubted matter of science, forms a new support to the same doctrine. The opposite view, once predominant, has been shrinking for ages into lesser space, and now maintains a footing only in a few departments of nature which happen to be less liable than others to a clear investigation. The chief of these, if not almost the only one, is the origin of the organic kingdoms. So long as this remains obscure, the supernatural will have a certain hold upon enlightened persons. Should it ever be cleared up in a way that leaves no doubt of a natural origin of plants and animals, there must be a complete revolution in the view which is generally taken of the relation of the Father of our being.
"This prepares the way for a few remarks
on the present state of opinion with regard to the origin of organic nature.
The great difficulty here is the apparent determinateness of species. These
forms of life being apparently unchangeable, or at least always showing
a tendency to return to the character from which they have diverged, the
idea arises that there can have been no progression from one to another;
each must have taken its special form, independently of other forms, directly
from the appointment of the Creator. The Edinburgh Review writer says,
'they were created by the hand of God and adapted to the conditions of
the period.' Now it is, in the first place, not certain that species constantly
maintain a fixed character, for we have seen that what were long considered
as determinate species have been transmuted into others. Passing, however,
from this fact, as it is not generally received among men of science, there
remain some great difficulties in connection with the idea of special creation.
First we should have to suppose, as pointed out in my former volume, a
most startling diversity of plan in the divine workings, a great general
plan or system of law in the leading events of world-making, and a plan
of minute, nice operation, and special attention in some of the mere details
of the process. The discrepancy between the two conceptions is surely overpowering,
when we allow ourselves to see the whole matter in a steady and rational
light. There is, also, the striking fact of an ascertained historical progress
of plants and animals in the order of their organization; marine and cellular
plants and invertebrated animals first, afterwards higher examples of both.
In an arbitrary system we had surely no reason to expect mammals after
reptiles; yet in this order they came. The writer in the Edinburgh Review
speaks of animals as coming in adaptation to conditions, but this is only
true in a limited sense. The groves which formed the coal-beds might have
been a fitting habitation for reptiles, birds, and mammals, as such groves
are at the present day; yet we see none of the last of these classes and
hardly any traces of the two first at that period of the earth. Where the
iguanodon lived the elephant might have lived, but there was no elephant
at that time. The sea of the Lower Silurian era was capable of supporting
fish, but no fish existed. It hence forcibly appears that theatres of life
must have remained unserviceable, or in the possession of a tenantry inferior
to what might have enjoyed them, for many ages: there surely would have
been no such waste allowed in a system where Omnipotence was working upon
the plan of minute attention to specialities. The fact seems to denote
that the actual procedure of the peopling of the earth was one of a natural
kind, requiring a long space of time for its evolution. In this supposition
the long existence of land without land animals, and more particularly
without the noblest classes and orders, is only analogous to the fact,
not nearly enough present to the minds of a civilized people, that to this
day the bulk of the earth is a waste as far as man is concerned.
Such reasoning as this naturally aroused bitter animadversions, and cannot have been without effect in creating an undercurrent of thought in opposition to the main trend of opinion of the time. But the book can hardly be said to have done more than that. Indeed, some critics have denied it even this merit. After its publication, as before, the conception of transmutation of species remained in the popular estimation, both lay and scientific, an almost forgotten "heresy."
It is true that here and there a scientist of greater or less repute - as Von Buch, Meckel, and Von Baer in Germany, Bory Saint-Vincent in France, Wells, Grant, and Matthew in England, and Leidy in America - had expressed more or less tentative dissent from the doctrine of special creation and immutability of species, but their unaggressive suggestions, usually put forward in obscure publications, and incidentally, were utterly overlooked and ignored. And so, despite the scientific advances along many lines at the middle of the century, the idea of the transmutability of organic races had no such prominence, either in scientific or unscientific circles, as it had acquired fifty years before. Special creation held the day, seemingly unopposed.