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.cort: 

 Epistriatum 

 Comm. hipp 

 Fornix 



Comm. 

 anterior 



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 medialis, which 

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

 compared with the jornix of the mammalian brain. 



No vestige of the nervus terminalis or its center has been recog- 

 nized in the amphibian brain. 



THE REPTILIAN BRAIN differs from the amphibian chiefly in 



