Cell and Protoplasm. in 



The attempt to delineate the structure of the frame- 

 work has led to very discrepant results, the most 

 important of which may be briefly summarized. 



(1) Reticular Structure. In 1864-1867 Frommann 

 and Arnold demonstrated in a variety of cells both 

 animal and vegetable the existence of a network-like 

 structure. To name those who have described this 

 reticulum would be to give a list of many of the most 

 illustrious histologists. 



(2) Fibrillar Structure. Not very different is the 

 view, which we may particularly associate with the 

 name of Flemming, that the structure is not so much 

 a network as a complex coil of tangled fibrils. 



(3) Granular Structure. There are a few histologists 

 who agree with Altmann (1886) that the cell-substance 

 consists of a homogeneous gelatinous matrix in which 

 granules are embedded, the granules being the impor- 

 tant vital units, bearing to the matrix the same sort of 

 relation that bacteria bear to the gelatinous stuff or 

 zooglcea in which they lie. 



(4) Emulsion Structure. Various critics, such as 

 Kolliker, Berthold, Fr. Schwarz, have from time to 

 time suggested that the reticular or fibrillar structure 

 was either a post-mortem appearance, or was simply 

 the optical expression of a really simpler structure like 

 that of an emulsion. This view must be especially 

 associated with the name of Biitschli, who has tried 

 ingenious experiments in the making of ' ' artificial 

 cells " from drops of fine emulsion, and has shown the 

 close resemblance between their structure and that of 

 cells. Biitschli's interpretation of cell -structure has 

 been received with much favour, yet a safer position is 

 perhaps that of those who doubt whether the structure 

 of cells is likely to be uniform. Thus Frommann, in 

 one of his last papers, maintained that some cells seem 

 vacuolar, that others look as if they contained a broken- 

 up network, but that in many a reticulum is, apart 

 from all vacuoles, distinctly demonstrable. Wiesner, 

 too, in a recent work suggests that the structure of 

 protoplasm may be a network, or a framework of inter- 

 woven threads, or a vacuolar honey-comb that it varies 



