322 



NERVOUS SYSTEM OF VERTEBRATES. 



missure and run backward through the hypothalamus to the 

 corpus mammillare. This is the fornix (colunma fornicis) and its 

 course is the same as that of the bundle called fornix in amphibia 

 and reptiles. Just above and behind the anterior commissure 

 the fornix column crosses the stria medullaris thalami which is 

 coming up from the nucleus amygdalae in the caudal part of the 

 ventral wall of the hemisphere. This region corresponds to the 

 lateral olfactory nucleus of lower vertebrates and the stria is 



Fig. 163. — Plan of cerebral hemispheres, lamina terminalis and optic thalami 

 in horizontal section. From G. Elliot Smith, b.o., olfactor\- bulb; f.M., foramen 

 of Monro; l.t., lamina terminalis; oJ., optic thalami; para., paraterminal body; 

 V.I., lateral ventricle; v. III., third ventricle. 



identical with the tractus olfacto-habenularis. The fibers which 

 join this tract from the fornix columns constitute the tractus cor- 

 tico-habenularis. Finally, a large tract (Fig. 164, j) runs up 

 from the region just in front of the optic chiasma through the 

 precommissural body and enters the fimbria to go to all parts of 

 the hippocampus. These fibers probably come from the lateral 

 olfactory area (pyriform lobe or nucleus amygdalae). They cor- 



