2o6 PROTOPLASM 



Frommann (1879-84). In living cartilage cells, filamentous 

 or reticular structures have been described by Flemming 

 (1870), Frommann (1879, 1880), and Schleicher (1879). 

 For colourless blood cells, Frommann (1875, 1880), Schwalbe 

 (1876), and Ley dig (1885) have affirmed the presence of 

 reticular structures, and Strieker (1890) has recently 

 photographed them from life, by which photograph Schafer 

 was converted from the opinion he held for so many 

 years, namely, that reticular structures were not present 

 in leucocytes. In the salivary corpuscles Strieker (1880) 

 described a trabecular framework. Moreover, there are 

 numerous assertions concerning the existence of striations in 

 epithelial cells in the living condition. Heidenhain observed 

 them in 1875 in fresh pancreas cells, Strieker and Spina 

 noticed striated structures in the fresh cells of the skin 

 glands of Amphibia (1880), Nussbaum (1887) in fresh 

 cells from the intestine of Anodonta, Ley dig (1885) 

 frequently confirmed the striated structure in fresh epithelial 

 cells of insects, and Carnoy (1885) expressly declares that 

 the reticular framework is to be made out plainly in the 

 living cells of insects. As is well known, Kupffer had 

 already described in 1870 a reticular framework in the 

 living follicle cells of the Ascidian ovum, and in 1874 

 in the cells of the salivary gland of Blatta ; he also saw 

 the reticular structures of liver cells, though more faintly, 

 in the fresh cell. 



In streaming vegetable protoplasm, Velten had already 

 (1873 and 1876) found the structures described above, and 

 Frommann also (1879) had frequently seen them there 

 beyond all doubt, even though many things which he 

 describes (especially in 1884) must have been pathological, 

 since he often investigated the cells for quite a long time 

 in sugar water; in fact he describes processes in them 

 similar to those which have been already mentioned, and 

 interpreted as pathological, in the case of the blood corpuscles 

 of the crayfish. On the other hand, the assertion of Schwarz, 

 that " these local reticular structures observed by Frommann 

 were nothing else than precipitates which separated out in 

 certain places " (of course in the cell sap), " and which later 



