260 FROM THE GREEKS TO DARWIN 



Le monde ambiant est tout-puissant pour une al- 

 teration dans la forme des corps organises. . . . La 

 respiration constitute, selon moi, une ordonnee si 

 puissante pour la disposition des formes animales, 

 qu'il n'est meme point necessaire que le milieu des 

 fluides respiratoires se modifie brusquement et forte- 

 ment, pour occasioner des formes tres peu sensible- 

 men t alter ees. 



This led him directly to an anticipation of the 

 ^survival of the fittest' or 'natural selection' hy- 

 pothesis of Darwin. The atmosphere, acting 

 upon the pulmonary cells, brings about "modifi- 

 cations which are favorable or destructive {'fu- 

 nestes' ) ; these are inherited, and they influence 

 all the rest of the organization of the animal be- 

 cause if these modifications lead to injurious 

 effects, the animals which exhibit them perish 

 and are replaced by others of a somewhat differ- 

 ent form, a form changed so as to be adapted to 

 {a la convenance) the new environment.'" This 

 is a very striking statement of a principle of 

 heritable variation due to the influences of en- 

 vironment, and of the survival or extinction of 

 types according to the adaptive or inadaptive 

 character of the variation. Perrier italicizes this 

 passage and points out its anticipation of Dar- 

 winism. 



Another highly characteristic feature of Geof- 

 froy's theory was that he included in it what has 



