150 



ANATOMY OF THE OENTEAL NEEVOUS SYSTEM. 



lus disappears in the midst of the Lobus olfactorius posterior, which, more- 

 over, is not, by superficial examination, to be differentiated from the stri- 

 atum, whose ventral portion it forms. 



The olfactory apparatus of amphibia has not yet been thoroughly 

 studied, but in reptiles and in mammals one can readily recognize that 

 many fibers pass into the base of the brain, into the Lobus olfactorius pos- 



CuiDmissura habenular 



Tr. olf. liabenul. titniie 



Nucleus taiuiiE 



Epistriatuin 



Origin of tlie tajnia 



Commiss. nut 



Median olfactory bund] 



Area olfact. 

 Striatum 



Ad lob. int. 

 Tr. bulbo-cort. 



f Biilbiis ; 



:■ olf. J 



flla-Jlf 



Fig. 98. — Schema of a horizontal section through the brain of Cyprinus 

 carpio, showing subdivisions of the corpus striatum; also the course of the olfac- 

 tory fiber-system. 



terior; also that fibers disappear in the Lobus olfactorius anterior. They 

 plunge in, to break up into fine terminal ramifications and come into rela- 

 tion with the dendrites of the large cells, — ^here called cortex-pyramids. 

 Corresponding with this distribution, we had to asstime two classes of fibers: 

 the Tr. bulbo-epistriatici and the Tr. hulbo-corticales ; in the last-named 

 tract were differentiated fibers for the anterior, and fibers for the posterior 

 portion of the olfactory lobes. Finally a connection probably also exists. 



