Ranson, Degej7erafiof2 in Spinal Nerves. 27 1 



an atrophy of the ganglion as a whole and of the nerve fibers con- 

 tained in it. There seemed to be some atrophy of the ganglion 

 cells but of this Homen could not be sure. He did not consider 

 the possibility of a decrease in the number of cells. Cassirer 

 ('98) states that a few cells in all probability undergo complete 

 destruction. He says that the question of the loss of spinal gan- 

 glion cells can only be settled by resorting to an enumeration. 

 Thus we see that in only four of the investigations were the spinal 

 ganglia studied and even in these cases no important observations 

 were made. 



Some additional data have been furnished by various investiga- 

 tions based on Nissl's axonal reaction. After cutting the sciatic 

 nerve near its exit from the pelvis in a number of dogs, Lugaro 

 ('96), found that not all the cells of the spinal ganglion showed an 

 equal degree of chromatolysis, a fact which he attributed to varia- 

 tions in the resistance of the individual cells. Thirty-nine days 

 after the operation, there was a manifest diminution in the number 

 of cells and an abundant proliferation of connective tissue. 

 Fleming ('97), who performed a similar operation on dogs and 

 rabbits, found a decrease in size of the spinal ganglion cells soon 

 after the operation. Cell destruction is, however, slow in making 

 its appearance; in only one case is "disintegration of the proto- 

 plasm" noted at six weeks; after 18 wrecks, however, many cells 

 have disappeared. Van Gehuchten ('97), aftercuttingthe vagus 

 in rabbits, observed that the majority of the nerve cells in the gan- 

 glion nodosum underwent complete degeneration and disappeared. 

 He believes that these results may be considered typical for the 

 spinal as well as for the cerebral ganglia. On the other hand, 

 Marinesco ('98), after a similar operation on the vagus of dogs, 

 found that the cells in the ganglion nodosum passed through the 

 phase of reaction to a phase of restoration, and, therefore, did not 

 undergo complete degeneration. In a rabbit six months after 

 the operation he could not find the cell destruction of which van 

 Gehuchten speaks. Marinesco also regards the reaction of 

 the vagus as typical for all the cerebro-spinal ganglia. Van 

 Gehuchten's observation has recently received support from 

 the observations of Kosaka and Yogita ('05), who found, 

 fourteen days after the section of the vagus in a young dog, an 

 almost complete disappearance of the cells of the ganglion nodosum; 

 of the thousands of cells only sixty-five remained. 



