340 



NERVOUS SYSTEM OF VERTEBRATES. 



other cells situated in deeper layers, and the end branches of the 

 neurites of various cells of deeper layers. 



2. Layer of small pyramids. This layer contains four types 

 of cells: (c) small pyramids, each provided with a number of 

 small basal dendrites and an apical dendrite which ascends to the 



Fig. 172. Diagram showing the probable course of impulses in the cerebral 

 cortex. From Cajal (Nouvelles idees, etc.). A, small pyramid; B, large pyramid; 

 C and D, polymorphic corpuscles; , terminal fiber from other centers; F, collaterals 

 from the white substance; G, fiber bifurcating in the white substance. 



plexiform layer, and having a long neurite which descends to the 

 white substance; (d) large cells with short neurites; (e) small 

 cells with short neurites which end in a very rich and dense arbor- 

 ization; (/) fusiform, ovoid, stellate or triangular cells without 

 radial dendrites whose neurites form the "fibers of Martinotti" 



