ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
271 
After sketching the various views held by prominent histologists, he 
proposes a classification, which, though tedious, will he useful. 
A. Cell hounded by a layer with single contour : — • 
The surface (Dujardin, 1848); 
The contact membrane (Max Schultze, 1863) ; 
The plasmic membran e (Pfeffer, 1890) ; 
The protoplasmic membrane (Delage, 1895). 
B. Cell hounded by a layer with double contour : — 
(1) Soft and plastic. 
The limiting or enveloping layer (Fol, 1879) ; 
The Grenzschiclit, zona limitans (His, 1897). 
(2) Resisting and inert. 
True cell-membrane (Waldeyer, 1895) ; 
The dead envelope (His, 1897) ; 
The cuticular membrane (Delage, 1895). 
With this paper, that by Prof. F. E. Schulze* * * § should be compared. 
Plasmocytes.f — Dr. Gustav Eisen has made an elaborate study of 
the blood of Batrachoseps attenuatus , a Batrachian common in California. 
The red cells vary enormously in size and shape, and very few of them 
are nucleated. But the most interesting feature of the blood is the 
presence of a new corpuscle, which Dr. Eisen has termed plasmocyte. 
He seeks to show that these plasmocytes are the remnants of the extra- 
nuclear part of fusiform corpuscles, which are remnants of erythrocytes ; 
that the plasmocytes consist of the archosomc — archoplasm and centro - 
somes — which has survived, while the nucleus has been destroyed ; that 
thisarchosome has surrounded itself with various envelopes of cytoplasm ; 
and that the plasmocytes have thus become free and independent 
elements of the blood. The present paper deals only with Batrachoseps , 
but the author has also found the plasmocytes in Phrynosoma , Diemyc- 
tylus, and in man. 
The plasmocyte may be defined as a corpuscle, generally without a 
cell-wall, always without a nucleus, consisting of the archosome and 
three spheres of cytoplasm. It shows powers of growth, movement, 
phagocytosis, &c. 
Distinction between Leucoblasts and Erythroblasts. J — Prof. A. 
Trambusti makes some observations on the extreme difficulty of dis- 
tinguishing between the young stages of red and white blood-corpuscles, 
and considers the various differentiating characters suggested by Yan 
der Stricht, Bizzozero, and others. He has found a secure differentia in 
the presence of granulations in the leucoblasts and leucocytes, demon- 
strable by double staining with safranin and indulin, or with thionin 
and eosin. 
Sympathetic Ganglion-Cells. § — Dr. A. J. Juschtschenco finds great 
uniformity in the sympathetic ganglia of Mammals. The cells are 
especially multipolar, with an axis-cylinder process and many proto- 
* Cf. this Journal, 3896, p. 607. 
t Proc. California Acad. Sci., i. (1897) pp. 1-72 (2 pis.). 
X Bull. Acad. Roy. Belg., xxxiii. (1897) pp. 333-41 (1 pi.). 
§ Arch. f. Mikr. Anat., xlix. (1897) pp. 585-607 (2 pis.). 
