lO EISEN. [Vol. XVII. 



the way they are arranged into threads or fibers. With the 

 light-filter the linin granules appear darker than the pure 

 cytoplasmic granules, and it is even possible under favorable 

 circumstances to follow the course of the linin granules from 

 their dispersion from the nucleus to their appearance in the 

 cytoplasm. 



While I have included the two spheres as a part of the cyto- 

 plasm, I nevertheless hold that they are of a somewhat different 

 nature, with different functions, from the cytoplasm proper. 



During the perfect resting stage of the large cell with poly- 

 morphous nucleus the cytoplasm proper is confined to a very 

 thin stratum surrounding the deeply folded nucleus. At that 

 time there is no distinction between the granules of the cyto- 

 plasm proper and the granules of the spheres (Fig. i), and 

 it appears as if the latter might later on be differentiated out 

 of the former, though we can with equal reason assume that 

 they are fundamentally different, but that they are intermixed, 

 and that they cannot be distinguished one from the other. At 

 a later period in the development of the cell such a distinction 

 is possible, as the staining capacity is much greater in the 

 granules of the spheres than in those of the cytoplasm proper 

 (Figs. 30, 58, 60). During this early resting stage of the 

 polymorphous cell the cytoplasm is never accumulated close to 

 the cell wall, but merely forms a very thin zone around the 

 nucleus (Fig. i). As the cell grows, this zone increases 

 in size and soon fills up all the available space between the 

 nucleus and the cell wall, though it is always denser in the 

 immediate vicinity of the nucleus (Figs. 3, 10, 12, 15, etc.). 

 In the early stages of this class of cells the cytoplasm proper 

 as well as the primitive spheres are composed principally of 

 granules, but at a later stage, when the spheres are formed, 

 the cytoplasm proper is generally distinguished by a fibrillar 

 structure, while the spheres are almost exclusively granular 

 (Figs. 34-37)- 



The Spheres. 



By the spheres I understand that denser accumulation of 

 cytoplasmic substance variously designated as spheres, archo- 



