30 CHARLES F. W. MC CLURE, 



In certain cells they may be equally distributed throughout the 

 cell body, in both the ecto- and endoplasmatic areas, Figs. 2, 3 

 and 4; while in other cells they appear to be lacking in the ecto- 

 plasmatic area. There is also some variation in their mode of distri- 

 bution at the axis - cylinder pole of the cell. In certain cells the 

 granules end abruptly in the cell body at the base of the axis-cylinder 

 process. Figs. 3 and 4; while in others they may extend for a short 

 distance into the base of the process, Fig. 2. 



The size of these chromophilous granules is so small, that their 

 measurement has proved impracticable; but on comparing them with 

 the fibrils of the axis-cylinder process, the diameter of the granules 

 was found to be much larger than that of the fibrils. This difference 

 in their diameter, in addition to the circumstance that the chromo- 

 philous granules are stained by the methylen blue, the fibrils of the 

 axis-cylinder process and neuroglia by the eosin, reduces to a minimum 

 any possibility of confusing these structures. This topic will be dealt 

 with more fully in connection with a critique of Rohde's papers. 



In respect to the individual form of these granules, the majority 

 may be said to be spindle-shaped, or in the form of little rods, 

 while others, which may be cross sections of these, have the ap- 

 pearance of little round dots. The manner in which these chromo- 

 philous granules are arranged in the cell body is, according to the 

 observations of the writer, closely related to the course of the fibrils 

 in that region, and will therefore be considered in detail in connection 

 with that topic. 



It may be stated here, however, that the chromophilous 

 granules are arranged chiefly in rows, but that at cer- 

 tain points in the cell body, they appear to be collected 

 into spindle-shaped groups which have their long axes usually 

 parallel to the periphery of the cell. 



In addition to the methylen blue- eosin preparations, these chromo- 

 philous granules are also well brought out by a combination stain 

 composed of safranin and light green. This method is a slight modi- 

 fication of one proposed by Benda and has been described on a 

 preceding page. 



Fig. 5 represents a section through a nest of ganglion cells in 

 an infra-oesophageal ganglion of Helix pomatia ^). It was drawn 



1) So far as observed by the writer, no fundamental difference in 

 structure exists between the ganglion cells of Helix and Arion which 



