130 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Bunge, R. — Ueber Geisselfarbung von Bakterien. (Staining Flagella of Bacteria.) 
Fortschr. d. Med., 1894, pp. 462-4. 
Vincent, H. — Sur un nouveau mode de coloration des microorganismes dans le 
sang. (On a new Means of Staining Micro-organisms in the Blood.) 
Compt. Bend. Hoc. Biol., 1894, pp. 530-1. 
(5) Mounting-, including- Slides, Preservative Fluids, &c. 
Preservation of Sea-weeds.* * * § — Dr. J. P. Lotsy recommends the follow- 
ing method of preserving specimens of Floridese, which prevents swelling 
of the cell-walls or contraction of the protoplasm, and preserves the 
chromatophores uninjured. The specimen is first laid in a 1 per cent, 
solution of chrome-alum in sea-water, and kept there for a period varying 
from 1 to 24 hours, according to the size and texture of the species. 
The chrome-alum is then completely washed out, and the specimen 
placed in a mixture of 5 ccm. of 96 per cent, alcohol in 100 ccm. water, 
and vigorously stirred. The amount of alcohol is then increased by 
increments of 5 ccm. every quarter of an hour until it amounts to 50 ccm. 
The specimen is then removed, and placed in a mixture of 25 per cent, 
alcohol in distilled water, and the quantity of alcohol again increased 
in the same way till it amounts to 50 ccm. alcohol to 100 ccm. of water. 
The same process is again repeated with 50, 60, 70, 80, and 90 per cent, 
solutions of alcohol in distilled water ; the specimens being finally 
preserved in the last. 
New rixing-material.j — Under the name “chrome-potash-sublimate- 
glacial-acetic-acid ” ( Chromkali-sublimat-Eisessig ) Herr Zenker recom- 
mends a fixing material for vegetable tissues which has the advantage of 
penetrating the tissue readily, without producing any shrinking. Its 
composition is as follows : — 100 parts distilled water, 5 sublimate, 2*5 
double potassium chromate, 1 sodium sulphate, 5 glacial acetic acid. 
It may also be used for preparations of the nervous system. 
(6) Miscellaneous. 
Cobalt-test for Transpiration.^ — The property of salts of cobalt of 
changing in colour according to the degree of moisture in the air, is 
employed by Prof. E. Stahl to determine the intensity of the transpira- 
tion from leaves. A useful material for that purpose is Swedish filter- 
paper which has been soaked in a 5 per cent, solution of cobalt chloride. 
This, when dry is intensely blue, passing, when moistened, through all 
shades to pale red. The freshly gathered leaf, or other part of the plant, 
is placed between two glass plates covered with freshly dried cobalt- 
paper. The amount of vapour given off by the leaf is shown by the extent 
of change in the colour of the paper. 
Action of Chemical Reagents on Vegetable Spermatozoids.§ — 
M. W. Belajeff states that if spermatozoids (of Characeee) are subjected 
to a 10 per cent, solution of sodium chloride, the central portion is 
quickly dissolved ; if previously stained with iodine-green, a rapid 
* Bot. Centralbl., lx. (1894) pp. 15-6. 
t Munch. Med. Wochenschr., xxvii. (1894) p. 532. See Bot. Centralbl., lx. 
.(!• 94) p. 45. % Bot. Ztg., lii. (1S94 l t0 Abtheil., pp. 118-9. 
§ Flora, lxxix. (1894) rganzungsbd., pp. 40-3. 
