EIGHTEENTH CENTURY EVOLUTIONISTS. 249 



species: "I hold that these supernumerary digits are, at their first 

 appearance, nothing but accidental variations. . . . But these varia- 

 tions once well established (confirmees) through a sufficient number 

 of generations in which both sexes have had them, constitute (fondent) 

 species; and it is perhaps thus that all species have multiplied." In 

 fact, for Maupertuis the difficulty lay in explaining, not how species 

 are transformed, but why they arc so stable. 



It will be seen that Maupertuis puts forward his theory of trans- 

 formation only as a likely hypothesis, not as a settled truth. But it is 

 an hypothesis for which he clearly enough indicates his own preference ; 

 and it is certain, from a passage of Diderot's which I shall presently 

 quote, that his contemporaries looked upon him as the typical repre- 

 sentative of the doctrine of the descent of all species from a primitive 

 type. Yet the significance and originality of the work of Maupertuis 

 lie not so much in his explicit enunciation of the theory of descent, as 

 in the fact that he (1) insistently called the attention of naturalists 

 to the problems connected with the genesis and transmission of varia- 

 tions; (2) framed a conception of the processes involved in embryogeny 

 and heredity which made the mutability of species seem antecedently 

 the more natural and more probable hypothesis; (3) indicated a pro- 

 gram for systematic observation and experimentation with reference 

 to heredity and to the effects of interbreeding, which, if carried out, 

 would have transformed zoology; (4) intimated that Nature produces 

 a far greater number of types and of individuals than she can main- 

 tain, and that among all these variant types there is constantly taking 

 place a process of natural selection whereby those unfitted to the con- 

 ditions of their life are exterminated; (5) explained the adaptation of 

 animals to their environment solely as the result of these conjoint 

 processes of variation and selection.* 



* Professor Osborn, unlike most of the historians of evolutionism, makes 

 some mention of Maupertuis, but classifies and describes his doctrines in a very 

 curious fashion. He classes the president of the Berlin Academy, as well as the 

 editor of the Encyclopaedia, with such 'evolutionists' as de Maillet (who 

 'derived man from Vhomme marin, the husband of the mermaid'), and Duret 

 (who asserted that there were trees in Scotland, the leaves of which, falling on 

 one side into the sea, became fishes, and falling on the other side on land, be- 

 came birds). Of all these equally Professor Osborn says: "They were not 

 actually in the main evolution movement ; they were either out of date or upon 

 the side-tracks of thought. They can be sharply distinguished from both the 

 naturalists and the philosophers in the fact that their speculations advanced 

 without the support of observation, and without the least deference to inductive 

 canons." Such a characterization, applied to men like Maupertuis and Diderot, 

 certainly fails somewhat in deference to the ordinary canons of historical ac- 

 curacy. Professor Osborn mentions, indeed, that 'an obscure article' (the 

 ' Systeme de la Nature) by Maupertuis ' has been unearthed in the course of 

 the present diligent search for all the prophecies of evolution,' and a partially 

 correct account is given of some of the contentions of that writing. But no clear 

 indication is given of the grounds of the evolutionism of Maupertuis ; and the 

 writer of ' From the Greeks to Darwin ' appears to have been unacquainted with 

 the ' V£nus Physique ' and to have ignored the work of Maupertuis in the re- 

 habilitation of the doctrine of epigenesis. He implies also that Buffon's theory 



