536 



THE NERVOUS SYSTEM 



The cell body of the neurone is the part that contains the nucleus and is 

 the center of those activities which influence the metabolism of the cell itself. 

 If the cell body be isolated from its processes, the processes will degenerate, 

 while the body continues to live. In other words, the cell body may be con- 

 sidered as the center of those trophic influences which regulate the nutrition 





B 



FIG. 358. Spinal Ganglion Cells from the Cat. A, Normal taken before stim- 

 ulation; B, taken after five hours' stimulation. From the right and left, eight thoracic 

 ganglia. (Hodge.) 



of the processes. Although the nerve cell as a whole is in many, perhaps in 

 most, cases a conducting organ, still those physiological processes which go on 

 in it produce marked changes in the protoplasm of the cell body. Hodge 

 has demonstrated that nerve cells which have been active for several hours, 

 in case of sparrows which have been flying about actively throughout the day, 



