288 EVOLUTION IN BIOLOGY. 



The " moule interieur " of Buffon is tlie aggregate 

 of elementary parts which constitute the individual, and 

 is thus the equivalent of Bonnet's germ, * as denned in 

 the passage cited above. But Buffon further imagined 

 that innumerable " molecules organiques " are dispersed 

 throughout the world, and that alimentation consists in 

 the appropriation by the parts of an organism of those 

 molecules which are analogous to them. Growth, there- 

 fore, was, on this hypothesis, a process partly of simple 

 evolution, and partly of what has been termed "syn- 

 genesis." Buffon's opinion is, in fact, a sort of combi- 

 nation of views, essentially similar to those of Bonnet, 

 with others, somewhat similar to those of the " Medici " 

 whom Harvey condemns. The " molecules organiques " 

 are physical equivalents of Leibnitz's " monads." 



It is a striking example of the difficulty of getting 

 people to use their own powers of investigation accu- 

 rately, that this form of the doctrine of evolution should 

 have held its ground so long ; for it was thoroughly and 

 completely exploded, not long after its enunciation, by 

 Caspar Friederich "Wolff, who in his " Theoria Genera- 

 tionis," published in 1759, placed the opposite theory of 

 epigenesis upon the secure foundation of fact, from which- 

 it has never been displaced. But "Wolff had no immedi- 

 ate successors. The school of Cuvier was lamentably de- 

 ficient in embryologists ; and it was only in the course 

 of the first thirty years of the present century, that Pre- 

 vost and Dumas in France, and, later on, Dollinger, Pan- 



* See particularly Buffon, 1. c. p. 41. 



