200 FROM LAMARCK TO ST. HI LA I RE. 



types according to the favourable or unfavourable 

 character of the variation. Perrier italicizes this 

 passage and points out its anticipation of Darwinism. 

 Another highl}' characteristic feature of his theory 

 was, that he included in it what has recently been 

 termed 'saltatory evolution^ and strongly opposed 

 Lamarck's fundamental principle that all transfor- 

 mation is extremely slow. It is evident that this 

 idea was suggested to him by the sudden transfor- 

 mations observed in his teratological studies. This 

 enabled him to maintain Evolution without de- 

 monstrating the existence of intermediate forms. 

 Intermediate forms had begun to be a stumbling- 

 block to evolutionists. Where, it was asked, was 

 evidence of a transition between amphibians and 

 reptiles, and between reptiles and birds? This 

 also enabled St. Hilaire to avoid a difficulty he 

 himself raised, that characters of new forms of life 

 would not be maintained pure, owing to the blends 

 of interbreeding; these sudden saltations or leaps 

 from type to type secured the necessary physiologi- 

 cal isolation. As a rapid transformationist, he was 

 not, however, an imitator of De Maillet, who, we 

 remember, believed in the transformation of adult 

 forms. St. Hilaire denied the possibility of these 

 rapid leaps in the adult condition, and believed that 

 they took place mainly in the embryonic condition ; 

 here, the underlying causes of sudden transformation 

 were profound changes induced in the egg by external 

 influences, accidents as it were, regulated by law. 



