No. I.] DESMOGNATHUS FUSCA. 267 



Cajal and Lenhossek. So that on this basis there may be 

 recognized three real spinal nerve roots — dorsal, lateral, and 

 ventral, the lateral being fused with the dorsal. The extension 

 of the cinerea in some regions of the myel to form the so-called 

 lateral horn may be correlated with the lateral root, and would 

 tend to confirm the view of its identity. This precocious 

 division of the fibers in the ganglia of the Desmognatlms into 

 three nerve trunks suggests quite naturally a possible correla- 

 tion with the presence of the three nerve roots. In this animal 

 the ventral root divides quite close to the myel, and some of 

 the fibers bend quite abruptly to enter the dorsal and latero- 

 caudal nerve trunks. I am rather disinclined, in this instance, 

 to accept Schaffer's view that these connecting rami contain 

 the motor elements of the dorsal root and the sensory elements 

 of the ventral root, but believe that the fibers passing from 

 these three nerve trunks into the dorsal root' are of an afferent 

 or sensory character, while those coming from the ventral root 

 are efferent, or motor, in nature; because it seems entirely 

 unnecessary in the dorsal and latero-caudal trunks, where both 

 kinds of fibers are represented, as well as in the ventral, to 

 reverse their course and send some of the motor elements 

 through the dorsal root and some of the sensory through the 

 ventral; or, to put it in another way: that the motor fibers 

 from the dorsal root and the sensory (.?) from the ventral 

 arrange themselves in the ganglion in such a way that the 

 nerves leaving 'the ganglion contain motor or sensory fibers 

 only as the case may be. It is only just to say that Schaffer's 

 paper deals almost entirely with the arrangement of the fibers 

 in the myel itself, and that the arrangement in the ganglion is 

 apparently an incidental observation; but his statement, if 

 carried to its logical conclusion, amounts to what has just been 

 said. 



The fibers entering the myel through the dorsal root were 

 seen in some cases to divide into a cephalic and caudal branch, 

 while in other cases no division was noted. Collaterals are given 

 off at various intervals into the cinerea; they end freely 

 between the cells; the ends are somewhat swollen, and the 

 whole collateral is relatively coarse in texture. The ganglion 



