156 Journal of Comparative Neurology, 



A further study of bichromate of silver preparations will 

 show that each fiber from one of these bundles after its separa- 

 tion from the rest becomes continuous with a fibrillar process 

 entering the calyx-cup from one of the cells above. Thus there 

 is formed a nerve cell of the general Y-type (fig. 18, Fl. XXI). 

 No other nerve cells are found in the cups. 



Before continuing the consideration of the fiber just noted 

 it may be well to mention the form of the cell bodies here and 

 of those elsewhere. The larger number of successful impreg- 

 nations of the cell bodies of the cups present a perfectly smooth 

 outline. Very many, however, have from one to five or six 

 projecting processes, which may branch. In this respect the 

 smaller cells of the pyramidal group are exactly like the larger 

 border cells, though such a condition did not happen to be 

 shown in the section from which figure 18 was drawn. To de- 

 termine whether they differed in this respect the sections of sev- 

 eral brains were examined, resulting in the conclusion just given. 

 Many of the cells resembled those shown in figure 19, PI. XXI. 

 Whether these processes are protoplasmic continuations of the 

 cells to which they are attached or whether they represent 

 merely filled up adjacent inter cellular spaces, is a rather difficult 

 question to answer. Here is one of the most serious difficulties 

 presented by the bichromate of silver method. A few such 

 cells I have seen in the optic lobes, but there as elsewhere cells 

 with smooth contours seem to be the rule, and the rule might be 

 taken to indicate an artifact nature for the processes in 

 question. Further than this I find no reason for believing 

 them to be artifacts. On the other hand, the fact that there 

 was no evidence of undoubted artifacts in the immediate neigh- 

 borhood of the cells described, together with the peculiar cir- 

 cumstance of the extremely small amount of extra-nuclear pro- 

 toplasm in the cells filling the cups and their generally crowded 

 appearance, would indicate that probably the processes are real- 

 ly parts of the cells with which they are connected. 



Returning to the fibers of these cells, it may be noted that 

 it is the bichromate of silver method alone that is able to show 

 their course and termination. Fortunately there is no difficulty, 



