the attempts which have been made in the name of science. Nor can these possess any interest for us until the time when it was at least possible to make a clear statement of the question, which was impossible as long as no clear definition had been given of organic species. In an historic account of the attempts which have been made to solve the question, it is useless, therefore, to go further back than Ray and Tournefort. The publication of Maillet in 1748 is the first attempt which deserves passing attention.

I do not intend to repeat here the account which I have given elsewhere of the different theories proposed by that talented author, by Buffon, Lamarck, Et. Geoffroy St.-Hilaire, Bory de St.-Vincent, and by Naudin, Gaudry, Wallace, Owen, Gubler, Kölliker, Haeckel, Filippi, Vogt, Huxley, and Mme. Royer. They all have this point in common; they connect the origin of the more highly developed species with transmutations undergone by inferior species. But there the resemblance ceases, and their theories frequently differ entirely on all other points. In short, their ideas may be arranged in two principal groups according as their authors favour a rapid or a gradual transmutation. The former admit the sudden appearance of a new type produced by a being entirely different: according to them the first bird came from the egg of a reptile. The latter maintain that the modifications are always gradual, that between one species and another a number of links have intervened which unite the two extremes. They consider that types are only multiplied slowly, and by a progressive differentiation.

In reality the first of these two theories has never been stated in such a manner as to form a real doctrine; it has never formed a school. The philosophers who promoted it confined themselves most frequently to pointing out, in a general manner, the possibility of the phenomenon, while they attributed it to some accident. At most they invoke in aid of this possibility, some analogies borrowed from the history of ordinary individual development, from that of

alternate generation, or of hyper-metamorphosis; they produce no definite fact in justification of their assertions.

With the exception perhaps of the hypothesis of M. Naudin, which we shall presently discuss, all these theories which favour a rapid transmutation deserve a still graver reproach, that, namely, of neglecting the great general facts exhibited by the organic kingdom. An explanation of the multiplication and the succession of principal or secondary types by some hypothesis is not sufficient. Special account must be taken of the relations which connect these types, of the order which rules the whole and which has been maintained from remote geological periods through all the revolutions of the globe, and in spite of changes in fauna and flora.

Accident, without rule or law, when invoked as the immediate cause of special transmutations, is obviously incapable of explaining this important fact; it gives no explanation whatever of the generality of fundamental types, and of the direct or lateral affinities which exist between their derivatives.

It is different with the theories which favour gradual transmutation. They deal with all these important questions, and give a more or less plausible solution of them. They start from a certain number of principles whose consequences more or less explain the whole question and many of its details. In a word, they constitute genuine doctrines and it is but natural that they should have gained a certain number of adherents.

Unfortunately these theories all have the same radical fault. They agree with a certain number of important facts, connected essentially with the morphology of beings; but they are in direct contradiction with the fundamental phenomena of general physiology, which are no less general or fixed than the former. This contradiction is not evident at first sight. This is the reason why these doctrines have influenced not only the public at large, but even men of the highest intellect, whose sole error consists in their having allowed themselves to consider one side of the question only.

All these theories have been consolidated into the doctrine which rightly bears the name of Darwin. At the hands of this illustrious naturalist, the hypothesis of gradual transmutation has assumed a force and appearance of truth which it never possessed before. Doubtless, long before Darwin, Lamarck had formulated his law of heredity and his law of development of organs, to which the English naturalist has added nothing; M. Naudin had compared natural selection to artificial selection; Etienne Geoffroy St.-Hilaire had promulgated the principle of the balance of organs; Serres and Agassiz had recognized in embryogenic phenomena the representation of the genesis of beings. But by taking as a starting point the struggle for existence; by explaining in this manner selection; by fixing the results of heredity; by replacing the pre-established laws of Lamarck by the laws of divergence, continuity, permanent characters and of finite heredity; by giving by these means an explanation of the adaptation of beings to all the conditions of existence, the expansive power of some, the localisation of others, the successive modifications of all, under the dominion of the laws of compensation, economy and of correlation of increase; by applying these facts to the past, present and future of animate creation, Darwin has formed a complete and systematic theory, the whole, and often the details, of which it is impossible not to admire.

I understand the fascination exercised by this profound and ingenious conception, which is supported by immense knowledge, and ennobled by his loyal honesty. I should doubtless have yielded as so many others have done, if I had not long understood that all questions of this kind depend especially upon physiology. Now, my attention once aroused, I found no difficulty in recognising the point at which the eminent author quits the ground of reality and enters upon that of inadmissible hypothesis.

I have thought it right to publish my criticisms upon the theory of transmutation, and upon Darwinism in particular. I was authorised to do so by the numerous attacks which

have often been made, in no measured terms, against what I consider to be the truth, and against every opponent of the new theory. But while refuting theories I have always respected the authors and done justice to their work. I have quoted the good as well as the bad, and have always held aloof from the ardent and lamentable polemics raised by transmutation,

I have had great pleasure, when occasion has offered, in defending the splendid researches made by Darwin in the natural sciences. For this very reason, and at the risk of being considered narrow minded, enslaved to prejudices and inable to leave an old groove, etc., etc., I consider myself entitled to attack Darwinism, if I employ none but the weapons of science.

III. There are some points in Darwinism which are perfectly unassailable. We may consider as the most important the struggle for existence, and selection which is the result of it. It is not the first time, certainly, that the former has been established, and the important part it has to play in the general harmony of the world has at least been partly comprehended. I will here only recall to the mind of my readers the fables of La Fontaine. But no one had insisted, as Darwin has done, upon the enormous disproportion which exists between the number of births and the number of living individuals; no one had investigated, as he has, the general causes of death or of survival which produce the final result. By pointing out the fact that each species tends to increase in number in geometrical progression, which is proved by the number of offspring to which a single mother can give birth during the whole course of her life, the English naturalist makes it easy to comprehend the intensity of the struggles, direct or indirect, which are undergone by animals and plants against one another and the surrounding world. It is, most certainly, entirely owing to this struggle for existence, that the whole world, in a few years, is not overrun by some species, or the rivers and ocean filled in the same

manner.

It is no less evident to me that the survivors cannot always owe their preservation to a combination of happy chances. Among the immense majority the victory can only be due to certain special advantages, which are not enjoyed by those who succumb. The result of this struggle for existence is, then, the destruction of all the inferior individuals, and the preservation of those individuals only which possess some kind of superiority. This is what Darwin calls Natural Selection.

I can scarcely understand how these two phenomena can be doubted or even denied. They do not constitute a theory, but are facts. Far from being repugnant to the mind, they seem inevitable, the consequences follow with a sort of necessity and fatality resembling the laws of the inorganic world.

The term selection gives rise to criticism, and the language of Darwin, at times too figurative, renders plausible the objection of those who have reproached him with attributing to nature the part of an intelligent being. The word elimination would have been more exact. But much of this should have been prevented by the explanations given by the author. Besides, it is evident that the struggle for existence entails the elimination of individuals who are less able to sustain it, and that the result exactly resembles that produced by unconscious human selection. Then heredity intervenes among beings which are free as well as among those which we bring up in captivity. It preserves and accumulates the progress made by each generation in any direction, and the final result is the production in the organism of certain appreciable anatomical and physiological modifications.

The words superior and inferior should here only be taken as relative to the conditions of existence in which animals and vegetables are placed. In other words the individual which is best adapted to those conditions, will be superior and will conquer in the struggle for existence. For instance, the black rat and the mouse have both to struggle against the brown rat which entered France during the last