302 



NERVOUS SYSTEM OF VERTEBRATES. 



hypothalamicus medialis curves down in front of the foramen 

 of Monro. 



In this figure there is shown also the root of the nervus terniinahs 

 which has its ending in the regio uncinata. The relations of the 

 end nucleus of this nerve to the adjacent olfactory nuclei and the 

 course of fibers arising in it have not yet been studied. 



The forebrains of ganoids and bony fishes can be treated 

 together as they are much alike. The forebrain is elongated, 



Tr. haben.-pedunc. 



Tr. olfacto-haljenula 

 Lat. olfact. nuc 



Fig. 148. — A diagram of the fiber tracts in the forebrain of a bony fish. The 

 figure follows in the main a figure by Goldstein, and is drawn on the same plan as 

 Figs. 146 and 147. 



the lamina terminalis is nearly horizontal, the lateral walls are 

 thick but not high and the whole roof as far forward as the olfac- 

 tory bulbs is membranous (Fig. 148). The median ventricle is 

 large and spreads out wide under the membranous roof and at 

 the cephalic end it bifurcates (foramina of Monro) into the ven- 

 tricles of the olfactory bulbs. In the thick lateral walls are found 

 nuclei corresponding to those in the selachian brain but much less 

 well developed. The corpus striatum occupies the chief part of 



