70 THE LOWER PRIMATES 



LEVEL OF THE OPTIC CHIASM (fIG. 34) 



At the level of the optic chiasm the decussation in the optic pathway 

 is "^the identifying feature (Opx). Another salient element is the optic 



FIG. 35. LEMUR MONGOZ. LEVEL OF THE ANTERIOR COMMISSURE. 



AC, Anterior Commissure; ciN, Internal Capsule; fdp, Descending Pillar of Fornix; for, Fornix; gh. Ganglion 

 Habenulae; glp. Globus Pallidus; nm. Nucleus Medialis Thalami; nli, Nucleus Lateralis InternusThalami; 

 NCA, Caudate Nucleus; put, Putamen; vq. Fasciculus of Vicq d'Azyr. [Accession No. 147. Section 417. 

 Actual Size, 20 X 10 mm.) 



thalamus which represents the last great Jelay station in the pathway 

 of all types of sensibility with the exception of olfactory sense. It com- 

 pletes the conduction pathway of body sensibihty. Dorsal to the optic 

 chiasm are crossing fibers which constitute the supra-optic commissure of 

 Meynert. Immediately dorsal to this is a large mass of gray matter con- 

 taining cells for the most part of the motor type and forming the globus 



