FROM LAINIARCK TO ST. HILAIRE 259 



the philosophical successor of Lamarck. It is 

 rather true that he took up the general doctrines 

 of transformism at the point where Lamarck 

 could no longer defend them. As a remarkable 

 coincidence, Buffon, Lamarck, and Geoffroy all 

 became transformists at the same age of life. 

 The younger St. Hilaire shows very clearly, as 

 do Quatrefages and Perrier, that he was more 

 properly the disciple and expounder of Buffon. 

 He denied the inheritance of adaptations or 

 modifications acquired by habit which formed 

 Lamarck's central thought, and maintained that 

 the direct action of environment was the sole 

 cause of transformation, always regarding organ- 

 isms as comparatively passive in their milieu. 

 Thus he found it necessary to greatly differen- 

 tiate and extend Buffon's conception of environ- 

 ment, especially on its chemical 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 sau- 

 rians. It was between 1825 and 1828 that Geof- 

 froy published his memoirs upon the fossil teleo- 

 saurs of Caen, and connected them by theoreti- 

 cal descent with the existing gavials.^ Changing 

 environment and respiration were, he believed, 

 the chief factors in this transformation:^ 



^Recherches sur de grands Sauriens trouv4s a Vetat fossile. 

 Paris, 1831. 



^Influence du monde ambianf pour modifier les formes animates. 

 Mem. Acad. Sci., XII, 1833, pp. 63-92. See pp. 76, 79. 



