136 Journal of Comparative Neurology. 



organs of the same name found in the hexapods. But from 

 the fact that their cells are of the chromatic cell type and simi- 

 larly situated and also from the fact that he seems able to recognize 

 nearly all the parts generally described in the organs in the hex- 

 apods it may here be suggested that they may possibly be the 

 homologues of these latter organs. There is needed, however, 

 a more minute and painstaking study than St. Remy has given 

 the structures before one should come to a definite conclusion as 

 to their homologies. 



The second of the three papers is that by Viallanes ( 93) 

 on "The neural centers and sensory organs of articulates " and 

 is mainly of interest here in showing this author's conception of 

 the minute structure of the nervous system. In his earlier pa- 

 pers he did not touch upon the matter, but in his last paper 

 one finds him following St. Remy's grouping of the cells and 

 adding a few ideas upon the finer structure of the fibrillar sub- 

 stance. These ideas were doubtless founded more upon the 

 general results obtained with the methylen blue and the Golgi 

 methods, which by this time had become very generally known, 

 than upon any observations of his own made by the aid of his 

 methods of staining. 



He describes and figures diagrammatically three kinds of 

 fibers. One of these, of large size, originates from large 

 cells and passes outside of the central nervous system after first 

 giving off in the latter a few short and fine branches. These 

 he calls motor fibers. Another kind, of much smaller size, enter 

 from cells outside the central system and branching more or less 

 profusely connect with the small branchlets of the first, forming 

 thus the terminations and connections of sensory fibers. 



The third kind are short, small fibers originating from 

 the chromatin cells and, branching profusely, connect with 

 the fine branchlets of the other two kinds of fibers. As will 

 be seen in subsequent pages, this general idea is supported by 

 facts, though, as indicated above, it was with Viallanes almost 

 purely hypothetical. 



The last of the three papers is one by Binet ( 94). This 

 author so far as the structure of the dorso-cerebron is concerned 



