THE CENTRAL NERVOUS SYSTEM. 



2. The stratum oriens, representing the fifth layer of the cortex, 

 and containing among the bundles of nerve-fibres numbers of spindle- 

 form cells, whose processes extend parallel with the free surface. 



3. The stratum cellularum pyramidalium, which corresponds 

 to the deeper portions of the third cerebral layer, and is conspicuous 

 on account of the large pyramidal ganglion-cells. The latter, 

 moderate in size (30-40 /*), are arranged in several closely-packed 

 rows, and send their axis-cylinder processes into the adjoining 

 medullary substance of the alveus, while their long apical proto- 

 plasmic processes pass towards the periphery and give to the outer 

 part of the third layer a vertical striation, which has received 

 recognition as 



4. The stratum radiatum. This layer consists almost entirely 

 of the long, tapering processes of the pyramidal elements, 



FIG. 345. 



C 



Diagram of the constituents of the cornu Ammonis, Golgi staining : fi, hippocampal convolution ; 

 C, cornu Ammonis ; F, fascia dentata ; i, fusiform, 2, 3, small and irregular, 4, 5, pyramidal, and 6, 

 small, cells of respective layers ; 7, 8, nerve-cells of fascia dentata ; al, collaterals of pyramidal cells ; 

 course of axis-cylinder processes shown by fine lines. (After Karl Schaffer.) 



which often show a disposition to divide into numerous branches 

 before reaching the border of the zone. 



5. The stratum lacunosum, composed principally of axis-cyl- 

 inders, which extend parallel to the fibre-layer of the alveus, to- 

 gether with the collateral processes from the neighboring nerve-cells. 



6. The stratum moleculare, which contains sparingly distributed 

 fusiform or pyramidal ganglionic elements, whose protoplas- 



