384 



TRACING OF IMPULSES. 



hippocampi. By the intermediate olfactory stria the impulses 

 enter the triangle and anterior perforated substance, and com- 

 plete their journey either in the same manner as given above or 

 via the anterior commissure. The lateral stria of the olfactory 

 tract conducts the impulses directly to the uncus of the hippocam- 



Central core of 

 ependymal cells 



Fibers to Ol. 

 tract. 



5. S. granulosum 



4. S. cellulare 

 3. S. reticulare 



2. S. glomeru- 

 losurn 



i. S. nervosum 



Nasal mucous 

 membrane 



Olfactory cell- 

 bodies 



Fig. 109. Chief elements of the olfactory bulb. (Gordinier after Van'Cehuchten.) 



pal gyrus. Note that olfactory impulses are chiefly, if not entirely, 

 uncrossed. 



Optic Path (Figs, no and in). Impulses of sight originate 

 in the rods and cones of the retinae and traverse three or more 

 series of neurones to the terminal nuclei of the optic tracts; namely, 

 the rod and cone, the bipolar, and the ganglionar neurones. 

 The axones of the last form the optic nerves and the visual part 



