Ranson, Alter ati on s in Spinal Ganglion Cells. 133 



that the cells with elongated conceutric granules are not present 

 in the cat, where Warrington and Griffith find the non-reactive cells 

 to be of the coarsely granular form. 



In the white rat, according to my own observations, the concentric 

 type is very rare, oidy t^^'o or three typical instances have been found. 

 On the other hand, a number of the medium sized coarsely granular 

 cells show a sufficient elongation of the granules to suggest somewhat 

 the other type. These cells in the spinal ganglion of the w^hite rat, 

 therefore, resemble closely the non-reactive coarsely granular cells 

 described by Warrington and Griffith in the cat, but also show some 

 affinity with the cells of Cox's Type II ; and it is of considerable 

 interest to note that, like these cells of the other investigators, they 

 also fail to react to lesion of the nerve. 



Since in my experiments only the dorsal ramus of the second 

 cervical nerve was cut and about 13 per cent of the total number 

 of afferent fibers running in the ventral ramus escaped lesion, 

 there are a few cells of all types which fail to react. While this 

 tends somcAvhat to obscure the picture, it is possible to determine 

 that the unaltered coarsely granidar cells are present in nearly as 

 great numbers as in the normal ganglia (Fig. 3) and it is clear that 

 few if any of the cells of this type have suffered alteration as the 

 result of the section of the nerve. These non-reactive cells in the 

 spinal ganglion of the white rat are all of medium size and present 

 a clear protoplasm with large chromatic granules which in some cases 

 show a tendency toward a concentric arrangement. These cells 

 are not very numerous, constituting only a small percentage of the 

 total number of cells. 



It is, therefore, clear that among the large cells of the ganglion 

 there are a few cells of a fairly definite type which fail to react 

 to a lesion of the nerve. These cells vary slightly according to the 

 animal used in the experiment. I believe that these are varieties 

 of a single type of cell and am inclined to accept the suggestion, 

 made by Cox, and Warrington and Griffith, that they represent 

 the cells of Dogiel's Type II (new types III, IV, VIIT, XI). 



There does not seem to be any adequate reason for a further 

 classification of the large cells so far as the arrangement of the 



