ST. HILAIRE. 199 



cal atmospheric side, attributing very marked results 

 to its influence upon the respiratory functions, as 

 in his account of the evolution of the crocodiles 

 from the saurians. 



It was between 1825 and 1828 that Geoff roy 

 published his memoirs upon the fossil Teleosaurs 

 of Caen, and connected them by theoretical descent 

 with the existing Gavials. 1 Changing environment 

 and respiration were, he believed, the chief factors 

 in this transformation. 2 



" Le monde ambiant est tout puissant pour une alteration des 

 corps organises. ... La respiration constitue, selon moi, une 

 ordonne si puissante pour la disposition des formes animales qu'il 

 n'est meme point ncessaire que le milieu des fluides respiratoire 

 se modifie brusquement et fortement, pour occasioner des formes 

 tres peu sensiblement alterees." 



The atmosphere, acting upon the pulmonary cells, 

 brings about " modifications which are favourable or 

 destructive (funestes ' ) ; these are inherited, and they 

 influence all the rest of the organization of the animal 

 because if these modifications lead to injurious effects, 

 the animals which exhibit them perish and are replaced 

 by others of a somewhat different form, a form 

 changed so as to be adapted to (a la convenance) the 

 new environment? This is a very striking state- 

 ment of a law of variation due to the influences 

 of environment, and of the survival or extinction of 



1 Recherches sur des grands Sauriens trouves & tetat fossile. Mem. Acad. 

 d. Sciences, Paris, 1831. 



2 Influence du monde ambiant pour modifier les formes animales. Mem. 

 de 1'Acad. d. Sc., XII., p. 63, 1833, 



