R ANSON, Altcr(iti()}is III spinal Gaiighon Cells. 139 



can be little doubt about the correctness of these earlier observations, 

 since the figures and descriptions given by these authors are very 

 clear, and agree in all essential points with each other. In some 

 of the illustrations it seems as if almost the entire quantity of 

 chromatic substance is accumulated in one solid mass which more 

 or less completely encircles the nucleus. Why this appearance was 

 not to be found in a single cell in my preparations is hard to under- 

 stand. It may be due to the fact that my animals were of a different 

 kind, but more probably is to be explained on the basis of the rapidity 

 with which the reaction occurred in my specimens. It seems probable 

 that the chromatolysis was so rapid that there was no time for the 

 clumping of the granules to occur before they were dissolved. Or 

 it may be that clumping occurred in the earlier stages but gave place 

 before the fifth day to complete chromatolysis. 



The Phase of Degeneraiion. Very little attention has been paid 

 to the degenerative changes which lead to the ultimate disappearance 

 of the cells. Lugaro found that scattered cells underwent complete 

 degeneration and became surrounded and penetrated by capsular 

 nuclei. This occurred from 15 to 40 days after the injury. Vacuolar 

 degeneration seemed to him to play a small part in the cell destruc- 

 tion. Fleming speaks of a "disintegration of the protoplasm" that 

 occurred in many cells 6 to 18 Aveeks after the operation. Cox gives 

 an excellent description of the degeneration by vacuolation. Ac- 

 cording to him the vacuoles are sometimes small, sometimes large 

 and multiple and in the latter case the l^issl-bodies have almost 

 entirely disappeared from the cell. If the vacuoles are very large 

 the nucleus vanishes, so that the cavity which represents the remains 

 of the earlier cell contains only the membranous ]iartitions between 

 the vacuoles. These membranes are impregnated with little granules. 

 In addition to this form of degeneration Kleist mentions another, 

 namely the gradual progressive atrophy of the cell resulting 

 at last in its complete disappearance. Koster is of the opinion 

 that the vacuolation is not the result of a pathological process but 

 is due to an error in technique. The cell destruction according to 

 him does not occur until late, mostly after the 284th day. One 

 sees then violet-stained protoplasmic remains which contain only 



