Biology and Its Makers / With Portraits and Other Illustrations

by William A. Locy

Cuvier and Saint-Hilaire.—In 1830 there occurred a memorable controversy between Cuvier and Saint-Hilaire. The latter (Fig. 118) was in early life closely associated with Lamarck, and shared his views in reference to the origin of animals and plants; though in certain points Saint-Hilaire was more a follower of Buffon than of Lamarck. Strangely enough, Saint-Hilaire was regarded as the stronger man of the two. He was more in the public eye, but was not a man of such deep intellectuality as Lamarck. His scientific reputation rests mainly upon his Philosophie Anatomique. The controversy between him and Cuvier was on the subject of unity of type; but it involved the question of the fixity or mutability of species, and therefore it involved the foundation of the question of organic evolution.

Fig. 118.—Geoffroy Saint-Hilaire, 1772-1844.

This debate stirred all intellectual Europe. Cuvier won as being the better debater and the better manager of his case. He pointed triumphantly to the four branches of the animal kingdom which he had established, maintaining that these four branches represented four distinct types of organization; and, furthermore, that fixity of species and fixity of type were necessary for the existence of a scientific natural history. We can see now that his contention was wrong, but at the time he won the debate. The young men of the period, that is, the rising biologists of France, were nearly all adherents of Cuvier, so that the effect of the debate was, as previously stated, to retard the progress of science. This noteworthy debate occurred in February, 1830. The wide and lively interest with which the debate was followed may be inferred from the excitement manifested by Goethe. Of the great poet-naturalist, who was then in his eighty-first year, the following incident is told by Soret:

"Monday, Aug. 2d, 1830.—The news of the outbreak of the revolution of July arrived in Weimar to-day, and has caused general excitement. In the course of the afternoon I went to Goethe. 'Well,' he exclaimed as I entered, 'what do you think of this great event? The volcano has burst forth, all is in flames, and there are no more negotiations behind closed doors.' 'A dreadful affair,' I answered; 'but what else could be expected under the circumstances, and with such a ministry, except that it would end in the expulsion of the present royal family?' 'We do not seem to understand each other, my dear friend,' replied Goethe. 'I am not speaking of those people at all; I am interested in something very different. I mean the dispute between Cuvier and Geoffroy de Saint-Hilaire, which has broken out in the Academy, and which is of such great importance to science.' This remark of Goethe came upon me so unexpectedly that I did not know what to say, and my thoughts for some minutes seemed to have come to a complete standstill. 'The affair is of the utmost importance,' he continued, 'and you can not form any idea of what I felt on receiving the news of the meeting on the 19th. In Geoffroy de Saint-Hilaire we have now a mighty ally for a long time to come. But I see also how great the sympathy of the French scientific world must be in this affair, for, in spite of the terrible political excitement, the meeting on the 19th was attended by a full house. The best of it is, however, that the synthetic treatment of nature, introduced into France by Geoffroy, can now no longer be stopped. This matter has now become public through the discussions in the Academy, carried on in the presence of a large audience; it can no longer be referred to secret committees, or be settled or suppressed behind closed doors.'"

Influence of Lyell's Principles of Geology.—But just as Cuvier was triumphing over Saint-Hilaire a work was being published in England which was destined to overthrow the position of Cuvier and to bring again a sufficient foundation for the basis of mutability of species. I refer to Lyell's Principles of Geology, the influence of which has already been spoken of in Chapter XV. Lyell laid down the principle that we are to interpret occurrences in the past in the terms of what is occurring in the present. He demonstrated that observations upon the present show that the surface of the earth is undergoing gradually slow changes through the action of various agents, and he pointed out that we must view the occurrences in the past in the light of occurrences in the present. Once this was applied to animal forms it became evident that the observations upon animals and plants in the present must be applied to the life of the fossil series.

These ideas, then, paved the way for the conception of changes in nature as being one continuous series.

H. Spencer.—In 1852 came the publication of Herbert Spencer in the Leader, in which he came very near anticipating the doctrine of natural selection. He advanced the developmental hypothesis, saying that even if its supporters could "merely show that the production of species by the process of modification is conceivable, they would be in a better position than their opponents. But they can do much more than this; they can show that the process of modification has affected and is affecting great changes in all organisms subject to modifying influences.... They can show that any existing species, animal or vegetable, when placed under conditions different from its previous ones, immediately begins to undergo certain changes of structure fitting it for the new conditions. They can show that in successive generations these changes continue, until ultimately the new conditions become the natural ones. They can show that in cultivated plants and domesticated animals, and in the several races of men, these changes have uniformly taken place. They can show that the degrees of difference so produced are often, as in dogs, greater than those on which distinctions of species are in other cases founded. They can show that it is a matter of dispute whether some of these modified forms are varieties or modified species. And thus they can show that throughout all organic nature there is at work a modifying influence of the kind they assign as the cause of these specific differences; an influence which, though slow in its action, does in time, if the circumstances demand it, produce marked changes; an influence which, to all appearance, would produce in the millions of years, and under the great varieties of conditions which geological records imply, any amount of change."

"It is impossible," says Marshall, "to depict better than this the condition prior to Darwin. In this essay there is full recognition of the fact of transition, and of its being due to natural influences or causes, acting now and at all times. Yet it remained comparatively unnoticed, because Spencer, like his contemporaries and predecessors, while advocating evolution, was unable to state explicitly what these causes were."