Zool— Vol. I.] EISEN—PLASMOCYTES. 57 



less regular than any of the plasmocytoblasts from the blood 

 of Batrachoseps. How much of this is due to the fixing 

 chemicals used in Bremer's preparations cannot be known 

 until comparative studies have been made with non-fixed 

 blood. The peculiarly shattered nuclear structures would, 

 it seems to me, certainly indicate that the paranuclear struc- 

 tures also had been considerably disturbed before finally 

 being fixed. A further study of these paranuclei is cer- 

 tainly of the highest importance. I have seen somewhat 

 similar bodies in the blood cells of Diemyctylus and Chon- 

 drotus, but not in Batrachoseps. 



The peculiar structureless bodies described by Rawitz 

 from the lymphatic gland of Macacus (Arch. Mikr. Ana- 

 tomie, Bd. 45, page 592) are possibly of the same nature 

 as my archosomes or plasmocyte. The want of structure 

 may be due to imperfect fixing methods employed. These 

 bodies occupy the same position in the cell as the Neben- 

 kern. The fact that they are set free in the lymph and prob- 

 ably reach the general circulation makes an homology 

 between them and the plasmocytes probable. 



Plasmocyte and Leucocyte. — It is appropriate that we 

 should compare the plasmocyte with the leucocyte in the 

 same blood, and search for some similarities as regards the 

 inner spheres. At the outset we find some very marked 

 differences pertaining to their staining qualities. Thus we 

 find that the Ehrlich-Biondi mixture, which is the most suc- 

 cessful stain to bring out the microcentrum of the leucocyte, 

 fails entirely to give any satisfactory images of the corre- 

 sponding parts of the plasmocyte; and, vice versa, the 

 toluidine does not stain the microcentrum of the leucocyte, 

 neither the spheres nor centrosomes. Another striking differ- 

 ence between the two kinds of corpuscles is the absence of 

 cytoplasmic rays in the fusiform corpuscle. Although care- 

 fully looking out for any trace of them I have failed to find 

 them in the plasmocyte. Now and then a star-shaped grano- 

 sphere occurs, both in the plasmocyte and in the plasmo- 

 cytoblast, but they are quite different from the filaments in 



