The finer Structure of the Nerve Cells of Invertebrates. 49 



Ground-Sulbstance. 



Little remains to be said concerning the ground-substance 

 ofthecell. In structure, it appears to be homogeneous, and in all 

 the sections mentioned above, stains lighter than the other elements 

 in the cell. In the methylen blue-eosiu preparations, it has already 

 been shown that the ground- subs tance is stained red by the 

 eosin, while in the safranin- light green preparations, 

 it is stained by the light green. 



A further Comparison of the Writer's Results with those 



of others. 



I wish here to speak particularly of Rohde's results, an outline 

 of which has already been given under "Literature". The following 

 statements refer to the nerve cells of Gastropods. Rohde's claim 

 that a fine fibrillar structure is characteristic of the axis-cylinder pro- 

 cesses of these cells, accords with my own investigations. It is also 

 not to be denied, that in general appearance and mode of staining, 

 these fibrils resemble certain fine fibrillar elements in the neuroglia 

 which envelops the cell; with the exception that the latter may stain 

 somewhat more deeply than the former. I regard these fine fibrils, 

 which are found among the course neuroglia fibrils, as extensions of 

 the primitive fibrils from the axis- cylinder process. 



Rohde's claim that a set of coarse fibrils are present in the body 

 of the cell, which are extensions of, and are similar in all respects to 

 the coarse neuroglia fibrils, I cannot substantiate. 



I find, as stated above, that the cell body usually contains in 

 addition to the ground-substance, only fine fibrils similar to those in 

 the axis-cylinder process, and a chromophilous substance in the form 

 of small granules which are arranged in rows upon or between fibrils, 

 and in groups (spindles). 



RoHDE has entirely overlooked the existence of a chromophilous 

 substance in these cells, and in my preliminary paper I stated that, 

 in all probability, his fine fibrils corresponded to my rows of small 

 chromophilous granules and his coarse fibrils to my spindles. After 

 a more careful study of my preparations , I have been obliged to 

 modify this view, and now feel convinced that his fine fibrils of the 

 cell body correspond to similar ones observed therein by me, and his 



Zool. Jalirb. XI. Abth. f. Morph. ^ 



