HOMOLOGY. 



23 



and gullet in Mollusks and Articulates with recognizable 

 structures in Vertebrates, I submitted to my Associates of 

 the Biological Section, D (British Association, 1881), the 

 facts and conclusions which led me to harmonize the oppo- 

 sitions, and to show that the ingenious idea of MM. Laurencet 

 and Meyranx, adopted and advocated by GeofFroy, was not, 

 in point of fact, open to the objection which relegated it to 

 the limbo of exploded notions, where it seems to have rested 

 now for half a century. 



I reproduce the diagrammatic illustrations (figs. 9 and 10) 

 by which Cuvier exemplified his objections, in order to show 

 how the homology I have propounded of the " conario-hypo- 

 physial tract " affects the argument and conclusion of the 

 great Anatomist. The sole liberty I have taken with that 

 diagram (fig. 10) is to add to the brain of the Mammal the 

 tract in question ( 7, 8) ; the significance of which to his argu- 

 ment Cuvier as little suspected as have his successors who 

 have devoted time and thought to the higher generalizations 

 of Biology. 



After demonstrating, by reference to the Badger, that 

 colour does not indicate the back of an animal, Cuvier pro- 

 ceeds to affirm that naturalists have for the recognition of 

 that aspect a more certain character, viz. the position of the 

 brain : — " lis ont pour reconnaitre les dos un caractere plus 

 certain : c'est la position du cerveau " *. 



Now, by the term "cerveau" Cuvier does not here mean 

 the sum of neural expansions usually called "brain," but 

 only one of them, that, viz., which he indicates (as in figs. 9 

 and 10) by the letter a in both Cephalopod and Mammal ; 

 it is the part which is termed the " supraoesophageal mass, 

 ganglion, or pair of ganglions" in Invertebrates, and the 



* Tom. at. p. 251. 



