566 



SIGNIFICANCE OF THE NERVOUS SYSTEM 



as the axons, but naturally, without becoming confluent or losing 

 their functional independence. In other places, they cross and give 

 rise to by-stations upon the general conducting path which is amplified 

 by the deposition of cytoplasm and nuclear material. Very clearly, 

 however, the fibrillar concept lays emphasis upon the conducting 

 element and attaches little importance to the cell-body. 



Fio. 281. Fig. 282. 



Fig. 281. — Cell from the Anterior Horn of the Spinal Cord of Man, Showing 

 Neurofibrils. 



ax, Axon; lil, spaces occupied by tigroid material; x, fibrillar connections between 

 neighboring dendrites. (Bethe.) 



Fig. 282. — Schematic Representation of the Neurofibrillar Connections in a 

 Pyramidal Cell of the Cerebral Cortex. (Cajal.) 



The fibrillar hypothesis is based upon structural and functional 

 evidence. Thus, it was found that the large ganglion cells frequently 

 display an intricate network such as is shown in Fig. 282. This net- 

 work was assumed to represent an intracellular ramification of fibrillse. 

 Bethe, moreover, has shown that in young animals the degenerating 

 peripheral ends of nerve fibers may regenerate without first having 



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