314 



NERVOUS SYSTEM OF VERTEBRATES. 



by any process of shifting be brought bodily into the position 

 occupied by the hippocampal commissure in mammals. More- 

 over, the presence in this commissure of the ascending tract 

 from the hypothalamus marks it as a part of the anterior commis- 

 sure. In amphibia, then, the commissural fibers of the hippo- 

 campal formation run by way of the anterior commissure, in which 

 they constitute a large bundle nearly separate from the rest of the 

 commissure. The presence of the tract from the hypothalamus 



Tr. olf.corf 

 Epistriatum 



Comm. hipp 

 Fornix 



Tr. strio-thalam' 



Fig. 155. — Transverse section through the forebrain of Lacerta at the level of 

 the anterior commissure. After Cajal (Textura, etc.). 



suggests that the olfactory cortex serves also as a gustatory cortex. 

 There is finally to be mentioned a small tract from the dorso- 

 caudal pole of the hemisphere which runs to the hypothalamus, 

 taking a course over and behind the anterior commissure and 

 separate from the tractus olfacto-hypothalamicus mediaHs, which 

 runs beneath the anterior commissure. This small tract is to be 

 compared with the fornix of the mammahan brain. 



No vestige of the nen^us terminahs or its center has been recog- 

 nized in the amphibian brain. 



The reptilian brain differs from the amphibian chiefly in 



