34 CHARLES F. W. MC CLURE, 



process and cell body is more pronounced than ever, the cell body 

 at this "Period" being stained so deeply, that no details of its gra- 

 nular structure can be definitely made out, while the axis-cylinder 

 process remains only slightly stained, and still contains faint parallel 

 striations (fibrils). 



Thus far, in the preceding pages, we have seen that there are 

 present in the bodies of the ganglion cells of Helix and Ärion, certain 

 structures of a granular character, which, of all the structures within 

 (nucleoli excepted), or of those surrounding the cell, alone possess a 

 great affinity for methylen blue, when the latter was used in com- 

 bination with eosin; while the fibrils, ground-substance and neuroglia 

 tissue are chiefly affected by the eosin. In addition to this, we have 

 also seen that these granules retained the safranin, when sections of 

 cells stained in this dye were washed out with acid solutions of light 

 green ; and that the fibrils , ground substance and neuroglia were 

 chiefly affected, in this case, by the light green '). 



Finally, we have found that freshly isolated cells progressively 

 stained in methylen blue, show the presence in the cell body of certain 

 granular structures which possess a marked affinity for methylen blue. 



We now turn our attention to a further study of these chromo- 

 philous granules, as seen in sections which have been prepared in a 

 manner somewhat different from the preceding. We will begin with 

 description of cells which have been fixed in Flemming's solution and 

 stained by Heidenhain's progressive iron-alum-haematoxylin method. 



Cells treated in this manner, present a marked difference as to 

 the mode in which their axis-cylinder processes and cell bodies are 

 stained. The cell bodies retain the stain much longer, or with greater 

 tenacity than the axis-cylinder processes , with the result that the 

 cell bodies always appear much more darkly stained 

 than their processes. 



In illustration of this fact, I call the reader's attention to Fig. 10, 

 which represents a small ganglion cell lying contiguous to an axis- 



1) The distinctive manner in which these chromophilous granules 

 are stained by methylen blue and safranin, makes it extremely difficult 

 to classify them, in accordance with Rohde's conception of nerve-cell 

 structure, with any of the fibrils within the cell, or with the neuro- 

 glia tissue surroundig it, which as we have seen are chiefly stained by 

 the eosin and light green. A further discussion of this question will 

 be given on a subsequent page, in connection with a comparison of the 

 writer's results withs those of previous investigators. 



