Zool.— Vol. I.] EISEN—PLASMOCYTES. 35 



ply that new centrosomes are budded off from the mother 

 centrosome, though this might be the case; but it may be as- 

 sumed that this budding is only a part of an amoeboid pro- 

 cess, an expansion which may later on be succeeded by 

 a corresponding contraction. 



The budding of centrosomes has already been ob- 

 served and described by M. Heidenhain in his " Neue Un- 

 tersuchungen," and he ascribes it to a process of centro- 

 somal division or multiplication. That such a multiplication 

 of the centrosomes in the plasmocyte takes place is almost 

 certain, but whether it ultimately leads to a division of the 

 plasmocyte remains yet to be demonstrated. 



The final effort of the centrosomes and somosphere is 

 probably to separate themselves in such a way that each 

 centrosome, with its surrounding somospheres, forms the 

 center of an archosome and a plasmocyte; but I think that 

 this division goes on principally while the microcentrum 

 is yet enclosed in the plasmocytoblast. After the plasmo- 

 cyte has once formed, division into two or more plasmocytes 

 may take place, though I have only very rarely found any 

 indication that this is the case. The impossibility of study- 

 ing the plasmocyte without proper staining and fixing makes 

 the determining of this most important question most diffi- 

 cult. In fixed specimens on slides I have now and then 

 found plasmocytes which appear to be in amitotic division, 

 but until special study has been given it this point cannot be 

 decided. 



Food Supply in the Somosphere. — Now and then I have 

 observed highly refractive globules in the somosphere, 

 which must either be parts of the somosphere, of secreted, 

 or of foreign matter. These globules may be two or three 

 in number, although usually there is but one. They are al- 

 ways dull yellowish, but strongly refractive, rounded or ir- 

 regular, with sharp outlines. They are not by any means 

 present in every plasmocyte, nor are they found on 

 every slide, though on some slides I find them in al- 

 most every plasmocyte. Since this paper was finished in 

 ms. I have found plasmocytes in large numbers in human 



