24 CALIFORNIA ACADEMY OF SCIENCES. [3D See.., 



that at one pole of the fusiform corpuscle the granosphere 

 is very large, while at the other it is small or even wanting. 

 This I think depends upon two things : either upon the stage 

 of development of the plasmocytoblast, or upon the absence 

 of or defect in the centrosomes or centrosphere.. Grano- 

 spheres which contain no archosome do not appear to 

 increase in size, nor do they separate from the vicinity of 

 the nucleus and become independent. While the plasmo- 

 sphere and hyalosphere often extend all around the nucleus, 

 forming the outer lining of the fusiform corpuscle, the 

 granosphere is always confined to the poles, as seen in figs. 

 21, 33, etc. Here it exerts a pressure on the nucleus, as it 

 is this sphere which causes the dell in the nucleus, generally 

 found at the poles. Between the granosphere and the nu- 

 cleus there is always a thin rim of hyalosphere, but as this 

 rim is even all around the nucleus it must be the grano- 

 sphere which is the direct cause of the dell. Further on I 

 will refer to this again, and then show that it is the granulated 

 sphere which in other genera of cells also causes a similar 

 dell. The density of protoplasm or the greater tension in 

 the granosphere, which causes this dell, probably could not 

 act in the absence of a cell wall, except for the apparent 

 elasticity and strength of the hyalosphere which prevents 

 the granosphere from escaping. The granosphere is more 

 or less sharply defined from the inner centrosphere. The 

 three outer spheres — plasmosphere, hyalosphere, and grano- 

 sphere — undoubtedly correspond to the ectoplasm of Heid- 

 enhain, a reference to which will be made further on. While 

 I have here referred to the granosphere as being the direct 

 cause of the dells in the nucleus, it is probable that the in- 

 direct cause of the dells is the archosome. 



The phenomena of phagocytosis will be referred to in an- 

 other place. Here I will state only that they are frequently 

 observed in the plasmocytoblasts as well as in the plasmo- 

 cytes, though principally in the latter. Both of these bodies 

 very often inclose parts of or whole red blood cells, which 

 they are apparently in the act of digesting. Such inclosures 

 are always found in the granosphere, from which it may be 



