NERVE-CELLS. 49 



ings may be entirely artificial, and that they do not demon- 

 strate the existence of two distinct substances in the tissue. 



The most interesting question with regard to the struct- 

 ure of the nerve-cells relates to the mode of origin of their 

 fibres, or poles. Until quite recently these have been re- 

 garded as simple prolongations of the substance of the 

 cells ; but lately the view has been advanced that the nerve- 

 cells, in the human subject, are composed of regular fibrils 

 continuous with the poles and starting, as it were, from 

 the nucleoli. 1 The fibrillation of the nerve-cells and their 

 prolongations is figured by Schultze in an article in one 

 of the most authoritative of the recent works on histolo- 

 gy ; a but some other eminent observers have failed to note 

 the appearances here described, 8 at least in the human sub- 

 ject and the mammalia. "With our , present knowledge of 

 the physiology of the nerve-cells, the question whether or 

 not their substance be fibrillated has little more than an ana- 

 tomical interest ; but there can be no doubt that the cells of 

 some of the lower orders of animals possess striations more 

 or less regular. These, indeed, were described soon after the 

 cells were discovered. While there is no anatomist who de- 

 nies the fact that the substance of the cells is marked by 

 stride in many animals, the existence of an analogous ar- 

 rangement in the human subject is still doubtful. Some 

 anatomists, with Schultze, admit the striations, but have 

 foiled to connect them with the nuclei and nucleoli. All 

 admit that they are demonstrated with great difficulty; and, 



1 BEALE, Indications of the Paths taken by the Nerve-currents as they traverse 

 the caudate Nerve-cells of the Spinal Cord and Encephalon. Proceedings of the 

 Royal Society, London, 1864, vol. xiii., p. 386, et seq. 



FROMMAXX, Ueber die Farbung der Binde- und Nervensubstanz des 



Ruckenmarkes durch Argentum nitricum und uber die Struktur der Nervenzellen. 

 Archiv fur pathologische Anatomic und Physiologic, Berlin, 1864, Bd. xxxi., S. 

 134. 



2 SCHULTZE, in STRICKER, Manual of Human and Comparative Histology, Lon- 

 don, 1870, vol. i., p. 179. 



KOLLIKZR, Elements d'histologie humaine, Paris, 1868, p. 332. 



