ST. HILAIRE AND CUVIER. 203 



speculation. The Buffon school came into ridicule 

 by some of the wild hypotheses in their earlier 

 books; for neither Buffon nor Lamarck knew when 

 to apply the curb. Excessive speculation brought 

 a reaction. After Kielmeyer, Schelling, and Goethe, 

 there was a return to the older methods of simple 

 observation and record. As we have seen, this was 

 partly justified by the fact that the whole philosophy 

 of the speculative writers, and much of that of 

 Buffon and Lamarck, was deductive, rather than in- 

 ductive. Geoffrey St. Hilaire sought to revive 

 speculation and place it upon the true inductive- 

 deductive basis in his Philosophic Anatomique. 



On the 1 5th February, 1830, matters came to a 

 crisis; St. Hilaire read before the Academy of 

 Sciences at Paris, in the name of Latreille and him- 

 self, a report upon the investigations of two young 

 naturalists. The conclusions reached in the report 

 were advanced in support of St. Hilaire's chief 

 doctrine of the universal unity of plan of com- 

 position ; this was his' central life thought, leading 

 him to emphasize the resemblances rather than the 

 differences between animals, and to lay the founda- 

 tion of the study of ' parallelism ' in development. 

 In this case he was illustrating his principle by the 

 supposed analogy between the organization of some 

 cephalopod molluscs and the vertebrates. It 

 seemed to Cuvier that these conclusions consti- 

 tuted a direct attack, and this brought on a discus- 

 sion of the questions which had been marking a 



