THE NEOPALLIUM. 



341 



which ramify in the plexiform layer. Cells of the last type are 

 found in all layers of the cortex and one is shown in the seventh 

 layer in Figure 171. 



3. External layer of medium and large pyramids. In addition 

 to (g) the pyramidal cells, whose form is well shown in the figure, 

 this layer contains several varieties of cells with short neurites, 

 two of which are shown in the figure. One of these (h) is found 

 in other layers as well. It has two sets of dendrites and a neurite 

 with a great number of regular, smooth branches. The second 

 (?) gives rise to a neurite which bears one or more pericellular 

 baskets ending about the bodies of pyramidal cells. 



4. Layer of small stellate cells and of pyramids, usually called 

 the layer of granules. This layer contains a few small, medium 

 and large pyramids similar to those in the adjacent layers, but the 

 most numerous and characteristic elements of the layer are the 

 small stellate cells. By reason of their great number and the 

 distribution of their neurites these cells are very important elements 

 of the cortex. They are of several varieties of which there are 

 shown in the figure : (j) cells whose neurites form long horizontal 

 branches in the fourth layer; (k) cells whose neurites ramify 

 in the third layer; (/) cells with ascending neurites with very 

 numerous and exceedingly fine branches; and (m) cells whose 

 neurites ascend to the first or second layer. 



5. Deep layer of large pyramids. In various regions of the 

 cortex are found discontinuous groups or islands of giant pyramidal 

 cells, two of which are showTi in the figure («). The layer contains 

 also cells with short neurites distributed to the fifth and sixth 

 layers, or ascending to the first layer. 



6. Deep layer of medium pyramids. This layer contains in 

 addition to the pyramids (0) and triangular (p) and fusiform cells 

 related to the pyramids, cells with short neurites of which several 

 are shown in the figure {q,r). 



7. Layer of triangular and fusiform cells. Some of the elements 

 of this layer are true pyramidal cells (s), others fusiform or tri- 

 angular cells (/) related to pyramids. The remainder are cells 

 with short neurites (u), including cells (/) which give rise to fibers 

 of Martinotti. 



