STRASSBURGER—LEYDIG 171 



off from the exterior by a thin enveloping layer formed of 

 the substance of . the framework. Eeinke is inclined to 

 admit that the spaces filled by the enchylema "become 

 partitioned off here and there by delicate diaphragms of the 

 substance of the framework," in which statement we may 

 perceive an approach to the theory of an alveolar structure. 

 In the figures which were added by Kratschmar to the 

 work of 1883, the reticular structure of the protoplasm of 

 j^thalium is represented rather fine and indistinct, but Ife 

 quite recognisable. 



From the year 1882 there come a few more contribu- 

 tions from other observers. Thus Freud again confirmed 

 the presence of net-like anastomosing fibres in the ganglion 

 cells of Astacus Jluviatilis without, however, having seen the 

 real minute protoplasmic network ; he therefore gave his 

 complete adherence to Schwalbe's conception of the structure 

 of ganglion cells. Paladino found reticular structures in the 

 cells of the endothelium of the Arachnoidea, and Schmidt 

 in the cells of the pancreas. 



Strassburger also now (1882, Zellhdute) came into 

 agreement with the more recent results of observation, 

 namely, that the structure of protoplasm was reticular, 

 but in the work which he published at the same period 

 upon the processes of division in the cell nucleus, etc., he 

 represented the protoplasm as a tangle of short twisted 

 fibres, after the manner of Flemming. Externally it was 

 supposed to be enclosed by a so-called " cuticular layer " 

 (Hautschicht), which arose by narrowing or obliteration of 

 the meshes of the framework, just as Schmitz had already 

 assumed. 



1883 brought with it two works of great importance 

 for the problem in hand ; first, the extensive investigations 

 of Leydig, which comprised observations upon very numerous 

 histological objects, and were amplified by a work that 

 appeared in 1885; and secondly, the investigations of 

 E. van Beneden, which were confined to the sexual organs 

 and sexual products of Ascaris megcdocephala. 



Leydig was able to observe distinctly the reticular or 

 spongy structure of the framework everywhere, both in fresh 



