CoGHiLL, Structure of the Nerz>e Cell. 187 



membranous walls of the vessel. Furthermore, the general form and posi- 

 tion of the spireme of Nelis harmonizes well with the canaliculus of 

 Holmgren. Though Nelis does not find nucleated membranous 

 walls, he does find parallel walls with a sharp contour. It only re- 

 mains to demonstrate the continuity of the structure with extracellular 

 lymph vessels in order to identify it with the canaliculus of Holmgren. 

 But as to the interpretation of Bochenek's clefts we find greater diffi- 

 culty. He has compared his preparations with the original prepara- 

 tions of the spireme made by Nelis and has decided that the two struc- 

 tures are totally different. He expresses himself as surprised, also, 

 that Holmgren should homologize the canaliculi of Helix with the 

 spireme. This suggests that Holmgren and Bochenek may be deal- 

 ing with altogether different structures. It maybe that Bochenek has 

 not seen the genuine canaliculus with membranous walls, but that he 

 has demonstrated only deep clefts in the cell which are filled with the 

 capsular tissue. 



The Nucleus. 



Holmgren ('99) finds that the size of the nucleus in the spinal 

 ganglia of Lophius varies with the size of the cell. The linin net and 

 chromatic granules, which stain red with toluidin blue and erythrosin, 

 are massed thickly around the nucleolus and radial branches stream 

 out from this to the nuclear membrane which is acidophile also. On 

 the side of the nucleus which lies nearest the center of the cell the 

 contour may become flattened or even indented by a mass of tigroid 

 substance which accumulates at this point. The nuclear membrane 

 of this region thickens and changes its reaction to the stain, for it now 

 stains dark blue in toluidin-erythrosin, deep black in iron haematoxylin 

 and green with the triple Biondi stain. Simultaneously with this 

 change in the nuclear membrane there come changes in the tigroid 

 mass, which is heaped upon the nucleus in this region. The large 

 tigroid bodies, which, earlier in the process, were packed closely to- 

 gether here, have become resolved into small granular heaps or scat- 

 tered granules suspended in a homogeneous or purely granular ground 

 substance. The latter stains blue with toluidin-erythrosin, gray or per- 

 haps black with iron haematoxylin and red with the triple acid stain. 

 Following this condition the thickened part of the nuclear membrane 

 disappears either throughout the entire extent or at intervals. Through 

 this cleft the cytoplasm becomes continuous with the karyoplasm. The 

 union takes place through protoplasmic bands (Ziige) which radiate 

 from the centrosome into the nuclear substance and become continuous 



