NERVOUS SYSTEM. VERTEBRATA. 



173 



part of the hippocampus to the neopallium above it and to the 

 precommissural area below it. (These features are perhaps 

 seen to better advantage on the back of the second slice.) 

 (Fig. 53.) 



Fig. 53. 



HIP. F. 



FASG . DENT. 

 CAP. INT. 

 PRCCCM.AREA, 



OLF .TUBER. 



The second section (fig. 54) passes through the two 

 cerebral commissures. The dorsal commissure is seen 

 passing into the alveus of the hippocampus on each side. 

 From this section it is possible to appreciate how the pallial 

 operculum descends on the mesial side of the hippocampus 

 toward the dorsal commissure, so as to shut out the fascia 



Fig. 54. (xli) 



FASC . DENT. 



_ALV. 



; f CAP. INT. 



dentata in a view of the mesial wall (compare the specimens 

 of the Black-faced Kangaroo) . 



The ventral commissure is seen (in the second section) 

 to split into two bundles in the corpus striatum. The 

 ventral bundle, which includes about half the fibres of the 

 commissure, passes transversely through the corpus striatum, 

 and joins the external capsule. This is the manner 



in 



