Hardesty, spinal Ganglion Cells. 3 1 



The distal excess realized, it might be natural to suppose 

 that many of these extra cells are such as send processes toward 

 the periphery without sending corresponding processes into the 

 dorsal root. After subtracting the motor or ventral root fibers 

 (col. F) from the sum found on the peripheral side of the gang- 

 lion (col. G), it is seen that there is still an average of more than 

 twice as many cells as there are fibers which can possibly be 

 considered as arising in the spinal ganglia. These ratios (col. 

 D) vary quite closely with the ratios having to do with dorsal 

 root fibers (col. C). By comparing columns C and D it appears 

 that there is in the Vth and Vlth nerves an average of about 

 one cell less per distal fiber than there were cells per fiber in 

 the dorsal roots, while in the IXth nerves this average is only 

 0.3 cells less. The Vth and Vlth are the nerves which have 

 relatively the larger amount of distal excess and absolutely the 

 larger percentage of distal excess. 



Many of these extra cells are allotted to the category of 

 the "DoGiEL spinal ganglion cell of Type II." However, none 

 of the descriptions of this type indicate that they are sufficiently 

 abundant in the ganglia to account for more than a very small 

 proportion of the excesses of cells found there. A larger pro- 

 portion of these extra cells belong probably to the anaxonic 

 type of neurone, latent. cells which have not yet developed pro- 

 cesses. BiJHLER and Hatai suggest that this type consists 

 among the smallest cells of the ganglia. In the nerves of the 

 frog here investigated, the proportion of small to large cells is 

 greater in the ganglia of the Vth and Vlth nerve than it is in 

 the IXth. This, however, is thought explainable on other 

 grounds. 



That the excess of cells above the number of dorsal root 

 fibers is greater than the excess above the fibers on the distal 

 side of the ganglion is no doubt due to some extent to certain 

 of the so-called multipolar cells described in the spinal ganglia 

 of various animals by Kolliker ('93), Lenhossek ('94), Spir- 

 LAS ('96), DoGiEL ('97), Cajal and Oloriz ('98) and others. 

 DoGiEL thinks that some of these may be modifications of his 

 cell of Type II. Others are thought to be of the character of 



