324 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
He placed in a glass cell a drop of peritoneal lymph of the frog, collected 
by means of a sterilized pipette. When the glass cover is added care 
must be taken to leave a little air round the lymph. If the examination 
be made at 15°, the amoeboid lymphatic cells, which are among the 
cells present, will be found to exhibit very lively movements. Most 
sink to the bottom, where they attach themselves to the glass, extend 
themselves, and become so delicate that they will disappear from the 
observer unless closely followed. At this stage they are very active, 
and multiply pretty rapidly by direct division. If the temperature be 
raised for one hour to 25°, some of the lymphatic cells which have given 
off arborescent prolongations more or less long and complex will be 
found immobile. To observe the structure of these clasmatocytes, 
M. Ranvier has fixed the elements with osmic acid, and stained them with 
violet 5 B or hex-ethyl violet, or he has fixed them with picric acid and 
stained with haematoxylin, and then eosin. It is only in fixed prepara- 
tions that the varied, complicated, and often sharp forms of the clasmato- 
cytes can be properly appreciated. 
Two Kinds of Chromatin.* — Prof. L. Auerbach finds that “chro- 
matin ” includes two kinds of substances, which stain in different ways 
and react differently to chemicals. The so-called “ achromatin ” consists 
for the most part of material belonging to one of the two chromatin 
substances. As one of these has a greater affinity for eosin, fuchsin, 
aurantia, carmine, and picrocarmine, while the other has a greater 
affinity for methyl-green, anilin-blue, and hsematoxylin, Auerbach 
proposes to call them erythrophil and cyanophil respectively. In 
studying these two substances he has been confirmed in his conclusion 
that the presence of an intra-nuclear network is casual and of secondary 
importance, not a fundamental fact of structure. The network some- 
times seen is due to a modification of the cyanophil, or less frequently 
of the erythrophil, or sometimes even of both, for a double network may 
occur. The erythrophil resembles the protoplasm of the cell-substance 
more than the cyanophil does. The latter has amoeboid mobility ; it 
forms the nuclear membrane when that is karyogenic or produced by 
the nucleus, and not cytogenic or produced by the cell-substance. 
Red Blood-corpuscles of Amphibians. f — Prof. L. Auerbach gives 
a precise account of these cells so often observed. They have a distinct 
cell-membrane. The cell-substance is divided into a cortical layer and 
a medullary substance. In adults there are normally many nucleoli in 
the nucleus. An apparent homogeneity of the nucleus often results 
from the method of examination, while a reticulate structure may be 
produced in certain conditions by modifications of the nucleoli. 
Nature and Varieties of Leucocytes.J — Dr. G. Lovell Gulland has 
prepared a critical and historical account of the varieties of leucocytes, 
which should be useful to those who are interested in the subject. 
Evacuation of Cell-nuclei.§ — Dr. R. Blanchard reports that he kept 
a specimen of Proteus anguineus with the object of studying its parasites. 
* SB. K. Preuss. Akad. d. Wiss. (1890) pp. 735-49. 
t Anat. Anzeig., v. (1890) pp. 570-8 (2 figs.). 
X Rep. Lab. R. Coll. Physicians Edinb., iii. (1891) pp. 106-56 (1 pi.). 
§ Bull. Soe. Zool. France, xvi. (1891) pp. 22-3. 
