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Page:Popular Science Monthly Volume 65.djvu/327

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SOME EIGHTEENTH CENTURY EVOLUTIONISTS.

SOME EIGHTEENTH CENTURY EVOLUTIONISTS. II.
By Professor ARTHUR O. LOVEJOY,

WASHINGTON UNIVERSITY.

II. Diderot.—Diderot was in even less degree than Maupertuis a contributor to the details of scientific knowledge; and the contrast between the work of the interpreter and that of the investigator of the facts of science is well shown in the relation of his theories to the discoveries of Daubenton. It was the great associate of Buffon who laid the foundations of the science of comparative anatomy, which was to furnish the most important arguments in favor of the theory of evolution; a French writer (Vicq d'Azyr) has even gone so far as to say that 'to the merit of having made a beginning of that science Daubenton has added the merit of having carried it through to completion.' After the publication of the third and fourth volumes of the 'Histoire Naturelle, 'an important body of facts and comparisons relating to the anatomy of the vertebrates was accessible to all readers; it is one of the most serious blots upon the reputation of Buffon as a man of science that he failed to appreciate the value of this body of detailed knowledge, and in a subsequent edition of the work cut out Daubenton 's anatomical contributions—to the great grief and disappointment of their author. Now the publication of the main facts of comparative anatomy brought clearly to light the striking homologies that run through the structure of all the vertebrate species. Daubenton himself, however, was not the man to see that these homologies suggested, and went far to justify, the hypothesis of the descent of all such species by progressive variation from a common ancestral prototype. His talent was not for the making of hypotheses, but for the collation of facts; he was a cautious and conservative man, capable of infinitely patient and accurate observation, but apparently not capable of penetrating to the significance of the facts which he observed. Even when the evolutionary hypothesis had been put forward by others, he gave it no encouragement; and it was apparently with the purpose of combating it that he contributed a paper to the French Academy of Sciences in 1764, arguing that the anatomical differences between man and the orangoutang are radical, and that man's general structure is elaborately adapted to the maintenance of the erect attitude, as the structure of the ape is not ('Memoires de l'Academie des Sciences,' 1764, p. 568). Similarly he argued, in his introduction to the natural-history volume of the 'Encyclopedic Méthodique' (1783), that man differs so essentially