430 % C. JUDSON HERRICK 



torius dorso-lateralis on the lateral border, thalamic connections 

 by way of the lateral forebrain bundle and striatum complex, 

 commissural fibers in both the commissura pallii anterior and 

 posterior, epithalamic connections by way of the stria medullaris. 



The two dorsal parts of the hemisphere, then, terminate in the 

 posterior pole. They do not directly connect with any dience- 

 phalic structures and their functional relations with the latter are 

 all effected by tracts which cross the di-telencephalic fissure in the 

 ventral part of the brain tube, i .e., ventrally of the sulcus medius, 

 either by way of the basal forebrain bundles or by way of the 

 stria medullaris. Although the latter receives fibers directly 

 from the caudal end of the primordium hippocampi dorsal and 

 caudal to the interventricular foramen (a condition which does 

 not prevail in mammals), nevertheless these connecting fibers 

 pass through the eminentia thalami (figs. 17 and 18) which cor- 

 responds in position to the ventral part of the lateral thalamic 

 wall (see pp. 476, ff) and not directly from dorsal telencephalic to 

 dorsal diencephalic centers. We shall find that the same condition 

 prevails in the frog, though the eminentia thalami is reduced 

 there to a small vestige which is crowded far dorsally. This 

 vestige in the frog is the nucleus supracommissuralis of the liter- 

 ature, which I shall term the nucleus of the commissura hippo- 

 campi. For further discussion of this nucleus see p. 440. 



The ventro-median part of the hemisphere merges with the 

 nucleus preopticus and this with the hypothalamus, these form- 

 ing a continuous column of grey, with the median forebrain tract 

 connecting all parts. This tract corresponds with the tractus 

 olfacto-hypothalamicus medialis of fishes and contains both 

 descending and ascending fibers. 



The ventro-lateral part of the hemisphere is characterized by 

 the lateral forebrain tract and is continued backward into the 

 prominentia fascicularis (Gaupp) of the thalamus, this prominence 

 being much more evident in the Anura than in urodeles. The 

 coarse fibers of this tract are clearly seen to reach all parts of the 

 ventro-lateral and dorso- lateral parts in the mid-region of the hemi- 

 sphere; they also reach the posterior pole. A larger proportion 

 of the fibers of this tract decussates in the anterior commissure 



