176 



THE HUMAN BODY. 



jority of which are granular and divide frequently in a forking 

 or " dichotomous" manner. These are known as the "proto- 

 plasmic" branches of the cell, and probably serve merely to 

 absorb nourishment for it. One branch,, however, a, gives 

 off at right angles smaller filaments, but still maintains its 

 individuality and ultimately becomes the axis cylinder of a 

 nerve-fibre. Its side branches probably put it in anatomi- 

 cal continuity with other nerve-fibres and other nerve-cells. 



FIG. 73. 1, Nerve-cell from anterior horn of gray matter of spinal cord; a, 

 axis-cylinder process. 2, Cell from posterior horn of spinal cord. 



Nerve-cells from the posterior hor-n of the gray matter of 

 the spinal cord (2, Fig. 73) also possess numerous granu- 

 lar protoplasmic processes, and a nerve-fibre process (b): 

 but this, instead of continuing directly into an axis 

 cylinder, breaks up into a network of fine branches which 

 frequently unite with one another and also, no doubt, 

 with fibrils from neighboring cells. It is almost certain 



