No. 3-] BLOOD-PLATES OF THE HUMAN BLOOD. 657 



ulin, degenerating cells, etc. ; but these plates do not possess 

 any constant and differentiated structure, nor any definite and 

 constant form. In healthy blood all the blood-plates are true 

 plasmocytes, and even in diseased blood the plasmocytes con- 

 stitute the only true blood-plates. 



5. For true blood-plates I propose to drop the word plates 

 and substitute the vioxA plasmocytes. 



6. In batrachian and reptilian, as well as in bird's blood, we 

 must recognize two distinct kinds of red blood-corpuscles 

 (erythrocytes) and two kinds of fusiform corpuscles. Each 

 kind of red blood-cell degenerates into a distinct kind of fusi- 

 form corpuscles. 



7. In AmpJnuma an4 NecUirus one class of erythrocytes is 

 oblong, the other more rounded. They possess, respectively, 

 the following characteristics : 



a. Oblong erythrocytes. 



Quite oblong ; nucleus oblong without depressions at the poles, 

 with uneven or warty outline. At the poles of the cells, far 

 from the nucleus, are found paired or single groups of granules 

 and globules, probably identical with centrosomes and grano- 

 sphere, and surrounded by a thin archoplasm. 



b. Rounded erythrocytes. 



More rounded, some entirely round ; nucleus rounded, with smooth 

 outline. Generally a depression at each pole, furnished with 

 the various spheres characteristic of a plasmocytoblast. There 

 are no separate globules at the poles. 



8. The two kinds of fusiform corpuscles partake of the same 

 general characteristics. They have been derived from the 

 erythrocytes through degeneration and are generally not pos- 

 sessed of a cell membrane. In the round fusiform corpuscles 

 the plasmocytoblasts are active, shown by increasing size ; but 

 in Nectiinis, Amphimna, Die7>iyctylus, Chondrotns, Pletlwdon, 

 and many others they do not develop into plasmocytes. 



9. The function of the globules and granules (centrosomes 

 with somospheres) in the oblong erythrocytes is probably a 

 mechanical one. It consists of so loading the poles as to cause 

 them to be directed forward, while the erythrocytes travel 

 through the capillaries. The advantage of such an arrange- 



