264 FROM THE GREEKS TO DARWIN 



was a return to the older methods of simple ob- 

 servation and record. As we have seen, this was 

 partly justified by the fact that the whole phi- 

 losophy of the speculative writers, and much of 

 that of Buffon and Lamarck, was deductive, 

 rather than inductive. Geoffroy St. Hilaire 

 sought to revive speculation and place it upon 

 the true inductive-deductive basis in his Philoso- 

 phie Anatomique, but he, too, finally failed. 



Beginning February 15, 1830, matters came to 

 a crisis: St. Hilaire read before the Academy of 

 Sciences at Paris, in the name of Latreille and 

 himself, a report upon the investigations of two 

 young naturalists. The conclusions reached in the 

 report were advanced in support of Geoffroy's 

 chief doctrine of the universal unity of plan of 

 composition; this was his central life thought, 

 leading him to emphasize the resemblances rather 

 than the differences between animals, and to lay 

 the foundations of what we now call 'parallelism' 

 or convergence in development. In this case he 

 was illustrating his principle by the supposed 

 analogy or parallelism between the organization 

 of some cephalopod molluscs and the vertebrates. 

 It seemed to Cuvier that these conclusions con- 

 stituted a direct attack upon himself, and this 

 brought on a discussion of the questions which 

 had been marking a widening gap between the 

 opinions of the two great schools founded re- 



