04 THE NERVOUS SYSTEM 



In good methylene-blue preparations and in sections stained by the newer 

 silver methods it is possible to make out many additional details of structure. 

 The axon may split into many branches, which subdivide and anastomose, 

 forming a true network in the neighborhood of the cell (Fig. 39, b). From this 

 network the axon is again assembled and passes on to a typical bifurcation. 

 Or the axon may be assembled out of a similar plexus which, however, is con- 



&. 



a 







Fig. 39. Neurons from the spinal ganglion of a dog: a, Small cells with unmyelinated axons; 

 6, c, d, e, and /, large cells with myelinated axons; /, typical large spinal ganglion cell showing 

 glomerulus and capsule. The arrow points toward the spinal cord. Pyridin-silver method. 



nected with the cell by several roots (Fig. 39, c}. Some of the fibers give off 

 collaterals terminating in spheric or pear-shaped end-bulbs. Such an end bulb 

 may rest upon the surface of its own perikaryon (Fig. 39, d] or elsewhere in the 

 ganglion. From the body of some cells short club-shaped dendrites arise, which, 

 however, terminate beneath the capsules which surround the cells. 



Based on such details as these Dogiel (1908) has arranged the spinal ganglion cells in 

 groups and recognizes eleven different types. Two of his eleven types are of special interest. 

 The cells of Type VIII resemble the typical spinal ganglion cell in all respects except that 



