ROHDE— STRUCTURE OF GANGLION CELLS 285 



with regard to the aggregate condition of the actual spongio- 

 plasmic framework when he says (i. p. 175), "It is firmer 

 than the. hyaloplasm (but perhaps not actually solid), and 

 is, in all probability, highly extensile and elastic." But a 

 highly elastic substance which is not actually of a solid 

 nature seems to me to be a physical impossibility, which 

 we cannot well make use of to found a hypothesis upon 

 living matter. 



In recent times Eohde has specially come forward as a 

 very zealous adherent of Leydig's theory. His investiga- 

 tions upon the nervous elements of the Annelids convinced 

 him also that the hyaloplasm alone must be the nervous 

 element, and that the spongioplasm, on the contrary, per- 

 forms functions of support exclusively throughout the entire 

 nervous apparatus. I think that the reasons for the 

 opposite view, which have been enumerated already, are 

 not shaken in the least by the investigations of Eohde, and 

 on that account I will not try to discuss them more thoroughly 

 here, the less so as his last work (1891) only became 

 known to me after the completion of my manuscript. I might, 

 however, point out the fact that the fibrillar structure of 

 ganglion cells, nerve fibres, etc., which Eohde alleges, does 

 not exist in the sense in which he interprets it. Eohde 

 takes up, in fact, about the same position as Flemming. 

 In opposition to him I hold my view of the structure of 

 ganglion cells, etc., to be entirely correct, and I think I am 

 the more justified in doing so as Eohde, in a photograph 

 of a section through one of the so-called peripheral ganglion 

 cells (Plate VII. Fig. B), has furnished, in my opinion, a 

 very valuable proof of the correctness of my view. 



The photograph in question shows the honeycombed 

 structure of the protoplasm very plainly almost everywhere, 

 and enables us to make out exceedingly well how the appear- 

 ances of fibres and striations arise solely by a modification 

 of the alveolar framework. If one compares this photograph 

 with the drawing of one of these cells which Eohde gives at 

 the same time (Plate VI. Fig. 12), it is very obvious not 

 only how little the latter corresponds to nature, and to 

 what a high degree it is schematised, but also that the drawing 



