204 FROM LAMARCK TO ST. HILAIRE. 



widening gap between the opinions of the two great 

 schools. Cuvier replied by a criticism of the posi- 

 tion of St. Hilaire as to this 'unity of plan,' and 

 rightly sought to demonstrate that there were 

 several distinct plans of animal organization. He 

 carefully analyzed the arguments brought forward, 

 and showed conclusively that in the types cited by 

 St. Hilaire the organs in their position gave evi- 

 dence simply of analogy and of resemblance, not 

 of a real unity of plan ; that these molluscs led to 

 no other types. Further, he said that St. Hilaire's 

 method contained nothing new, and reverted simply 

 to the views of Aristotle. 



In following the details of this discussion, we 

 see that Cuvier was entirely correct in his facts, 

 and wrong in his principle; while St. Hilaire was 

 wrong in his facts, and right in the principle which 

 he advocated. The effect was to drive Cuvier, who 

 issued with the greater eclai, into the extreme posi- 

 tion of recommending naturalists to confine them- 

 selves solely to the exposition of positive facts with- 

 out attempting to draw from them inductions. 

 This sharp issue, therefore, exerted a retarding 

 influence upon the progress of inquiry into Evo- 

 lution ; for Cuvier, in his brilliant lectures in the 

 College de France, threw increased weight against 

 the method and teachings of St. Hilaire, as he 

 had previously done against those of Lamarck. 



BoRY DE Saint Vincent (1780- 1846) seems to 

 have been the only loyal successor of Lamarck in 



