ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
G8i 
(2) Preparing- Objects. 
Preparation and Fixing of Algae.* * * § — Prof. F. Oltmanns recommends 
the following process for the Florideas. The algae are placed in chromic- 
potassium-sublimate-glacial-acetic-acid, or in Rath’s picrin-osmium- 
platinum-chloride-acetic-acid, and then, after a short time, in 70 percent, 
alcohol, until they no longer impart to it a yellow colour. Rath’s mixture 
fixes the chromatophores well. The preparation may then be stained by 
haemalum or by very dilute solution of haematoxylin (at 60° C.), or by 
Heidenhain’s haematoxylin-iron-alum. Carmin does not answer so well. 
Isolating Ganglion-cells and TJnstriped Muscle-fibres.f — Accord- 
ing to Herr J. Arnold, ganglion-cells and unstriped muscle-fibres are 
easily isolated by the iodo-potassic iodide method. The objects may be 
placed for 2-3 days in 10 per cent, potassium iodide solution, and then 
for a similar time in iodopotassic iodide solution (5 drops of the strong 
solution to 10 ccm. of 10 per cent, potassium iodide solution), or the latter 
mixture may be employed from the start. In the first case the cells are 
better isolated, in the second they preserve their form more perfectly. 
It is a very good thing to add a few drops of an aqueous solution of 
eosin to the isolating fluid. 
Methods for Demonstrating Myxosporidia.J— Herr F. Doflein used 
for his investigations on Myxosporidia material derived from sea- and 
fresh- water fish. It is indispensably necessary that living and fresh 
material should be studied, as the study of the finer morphology of the 
spores is a matter of extreme difficulty in clarifying media. The best 
fixative was found to be Flemming’s solution, though sublimate, picro- 
acetic acid, and picro-sulphuric acid can be used with advantage, espe- 
cially as after the latter reagents carmin stains can be employed ; for, 
as is well known, after Flemming’s solution these stains are not extremely 
successful. In order to obtain preparations of the forms inhabiting the 
urinary and gall-bladders, the following method was adopted. A drop 
of the fluid in which Myxosporidia were suspended was spread on a 
slide and fixed with one of the before-mentioned fluids. If the bile 
would not coagulate a little blood was added. In this way a crowd of 
Myxosporidia are fixed in a thin film, and can be further treated as a 
section. After fixation in Flemming’s solution, the best pigments were 
safranin and gentian- violet, and the haematoxylin- iron. After the other 
fixatives, borax-carmin, Mayer’s carmin, haematoxylin, haemalum, haemato- 
xylin-eosin, or orange G, Bismarck-brown, and methylen-green were 
useful occasionally. For showing up the walls and margins of cells, 
indulin is a useful accessory to iron haematoxylin. 
Method for Demonstrating the Shape of Spaces and Passages in 
Embryos.§ — Herr F. Hochstetter communicates an ingenious method 
which he devised for showing the changes occurring during the develop- 
ment of the membranous labyrinth. This method, with modification and 
* Bot. Ztg., lvi. (1898) l te Abth., p. 100. 
f Arch. f. Mikr. Anat., lii. (1898) pp. 762-73(1 pi.). See Zeitschr. f. wiss. Mikr., 
xv. (1898) p. 226. 
X Zool. Jakrb. (Abtli. f. Anat. u. Ontog.), xi. (1898) pp. 281-350 (7 pis. and 
20 figs.). See Zeitschr. f. wiss. Mikr., xv. (189S) pp. 217-8, 
§ Zeitschr. f. wiss. Mikr., xv. (1898) pp. 186-92 (1 pi.). 
