Steerer. MF MERE Rie At) ite Soe tet 
1885.] Fhystology: 1239 
authors. The first of these consists merely of detached pieces of 
the nuclein or chromatin filament. The second kind of nucleolus 
is only a nucleus in miniature, and is quite independent (Stras- 
burger to the contrary) of the chromatin filament. This nucleolus 
is a reserve fund for the use of the nuclear protoplasm and true 
nucleoli disappear during the process of cell-division. The 
membranes of cell and of nucleus are identical in their general 
characters, 
The peculiar parallel streaks which are found connecting the 
two rosettes of chromatin substance after these have separated 
during cell-division, Carnoy declares to be formed by the fibrils ` 
of the reticula found in the membrane and protoplasm of the 
mother nucleus, the parallelism being caused when the mother 
nucleus pulls itself apart. fter complete formation of the 
daughter nuclei, the parallel fibrils become again transformed 
into the protoplasmic reticulum of the new cells. A rather full 
list of references to work on this subject may be obtained by 
consulting Carnoy, of. cit.; Flemming, Virchow’s Archiv, 1879, 
Bd. 77, p. 1; Arnold, same volume, p. 181. The English reader 
may find a good general review of the subject in Quart. Fourn. 
Mic. Sci., 1882, p. 35. 
THE PHYSIOLOGICAL CHEMISTRY OF THE KIDNEY.—It has been 
made almost certain by the various labors of Ludwig, of Heiden- 
hain and of Nussbaum, that the kidney tubules where lined by 
cells containing considerable protoplasm are differentiated in their 
function from the thin walled Malpighian capsules at the ex- 
tremities of the tubules, The commonly received opinion is that 
the wall of the capsule serves simply as a diffusion and filtration 
membrane through which pass water and inorganic salts which 
make up the bulk of the urine; while the large-bodied cells of 
the tubules, particularly of the convoluted portions, may be 
looked on as true secretory mechanisms which have the power of 
actively selecting certain substances, as urea and urates, from the 
lymph, and probably also of manufacturing specific products. 
Dr. Dreser comes forward to extend the evidences for a differen- 
tiation of function between the two parts of the secretory mechan- - 
ism of the kidney. Dreser, experimenting on frogs, thinks he 
has shown that the fluid passed through the capsules of the kid- 
ney is alkaline, while that secreted by the convoluted portions of 
the tubules is acid in reaction. 
The results of the work depended upon the peculiar behavior 
of “acid fuchsin” toward alkalies and acids respectively; the 
former render it colorless, while the latter restore its red tint. 
five per cent to ten per cent solution of acid fuchsin is injected 
into the lymph sac of a frog and in half an hour the urine, drawn 
by a catheter, is distinctly red. If sufficient material be injected 
the red tint of the fluid becomes less deep, but still is immediately — 
VOL, XIxX.—NO. XII, 8r 
