R ANSON, Altcratiuiis ill Spinal Ganglion (^rlls. 137 



connected only with its central and peripheral processes ; but is in 

 reality a complicated mass containing the ramifications of dendrites 

 and axis cylinders, forming exceedingly intricate intercellular mesh- 

 works and pericellnlar baskets, the cells in this w^ay being brought 

 into close functional relation with each other." We will now study 

 the reaction in the different tyjies of cells to see if there is any 

 evidence that the reaction in some cells is secondary to that in 

 others. 



It has been shown in a previous paper that the evidence points 

 to the small cells as those not associated with medullated fibers, and 

 it is, therefore, in these cells that w^e would expect to find evidence 

 of the secondary nature of the chromatolysis. ISTevertheless, the 

 evidence shows that the small cells are the ones most susceptible 

 to a lesion of the nerve. According to all observers wdio have made 

 any statement in this connection, the small cells are the first cells 

 in the ganglion to react. This fact is entirely at variance with the 

 idea that their reaction is secondary to an axonal reaction in the 

 large cells. 



According to Lugaro the small dark cells are rapidly altered, 

 the reaction reaching its height by the fourth day, while the reaction 

 in the other cells does not reach its maximum until the fifteenth 

 day. The cytoplasm of the small cells is pale, especially at the 

 center, and the nucleus has been displaced to the periphery. Cox 

 found that the small cells showed alterations as early as twenty- 

 four hours after, the operation and by the end of the fourth day 

 most of them were very much altered, wdiile the large cells were just 

 beginning to show chromatolysis. All the other observers agree that 

 the small dark cells show chromatolysis but do not say at w^hat time 

 the reaction occurs. There can, therefore, be no doubt that most of 

 the small dark cells react to the injury of the nerve and do so earlier 

 than the large cells. It must be borne in mind, however, that not 

 all of the small cells react in this way. As will be remembered, 

 a few of the smallest cells do not present a dark cytoplasm, but 

 are clear cells w^th a few large chromatic granules. Lugaro, War- 

 rington and Griffith agree that these cells never show chromatolysis. 

 According to the last two observers there are also a few of the 



