N THE HIPPOCAMPAL GYRUS 



515 



larger, the thick fibre layer in the deeper part of the molecular 

 stratum, the abundance of granule cells, the paucity and irregular 

 form of the pyramidal cells, and finally the presence in the inner 

 stripe of Baillarger and in the outer portion of the deep poly- 

 morphous cell layer of numerous large isolated multipolar cells, 

 the giant " solitary cells " of Meynert. 



IN THE AUDITORY AREA temporal lobe the seven layer type 

 is found. Its structure in this area is apparently identical with that 

 previously described for the seven layer type in the parietal lobe. 



IN THE RHINENCEPHALON several peculiarities of cell 

 formation are found. That occurring in the olfactory bulbs will 

 be briefly considered in connection with the course of the olfac- 



FIG. 399. DIAGRAM OF THE CORNU AMMONIS AS SHOWN BY THE GOLGI STAIN. 

 al, collaterals of the pyramidal cells ; (7, Ammon's horn ; F, dentate fascia ; H, hippo- 

 campal gyrus. 1-8, typical cells of the several layers ; 1, fusiform ; #, 3, small poly- 

 morphous; 4i 5, pyramidal ; 6, small polymorphous; and 7, 8, cells of the dentate fascia. 

 (After K. Schaffer, from Piersol.) 



tory tracts (page 555). The olfactory area of the hippocampal 

 gyrus and the peculiar formation of the cornu Ammonis deserve 

 mention at this time. 



IN THE HIPPOCAMPAL GYRUS the outer polymorphous cells 

 exhibit a special tendency to group formation. The pyramidal 

 cells form a tier of considerable thickness, but are of irregular 

 shape. The cortex as a whole is comparatively thin. It presents 

 the following layers : 



