ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
803 
diverse organs can be consistently stained. Portions of tissue fixed in 
alcohol are cut in paraffin ; sections, fixed upon the slide, are stained 
with anilin-gentian-violet for 10-20 minutes. After treatment for one 
minute with lugol solution of a port wine tint, the preparation is dried 
with filter-paper and decolorized with anilin-xylol. Mount in xylol- 
balsam. 
Fat as affected by Osmic Acid.* * * § — Dr. B. Solger directs attention 
to a communication which he made ten years ago on the effect of osmic 
acid on fresh fatty tissue. It separates the fatty substance into a firmer 
(peripheral) and a more fluid (central) portion. The former probably 
consists of palmitin and stearin, the latter of olein. This effect of osmic 
acid does not seem to have been sufficiently appreciated. 
Double Staining of Vegetable Membranes, j — M. Ch. Roulet treats 
sections of vegetable tissue by placing them for a quarter of an hour in 
a saturated alcoholic solution of cyanin. The sections have been 
previously decolorized in eau de Javelle. From the cyanin solution 
they are transferred to spirit, and then for 15 minutes to a 5 per cent, 
ammoniacal solution of Congo-red. Having been again washed in spirit, 
the preparations are mounted in xylol balsam. The cellulose mem- 
branes are stained red ; the ligneous blue. 
As a mounting medium for sections stained with Genfer’s solution 
(2-5 per cent, ammoniacal solution of Congo-red with a 0*5 per cent, 
chrysoidin) the author prefers glycerin or Venetian turpentine to Canada 
balsam. Glycerin-jelly is less advantageous than pure glycerin. 
Method of Staining the Cilia of Living Bacteria.;]; — M. Strauss 
places a loopful of a bouillon culture 1-3 days old of Spirillum cholerse 
asiaticse , Metschnikovi , or Finkler-Prior upon a slide, and then adds a 
loopful of Ziehl’s solution diluted with three or four times as much water. 
The two are thoroughly mixed, a cover-glass is imposed, and the pre- 
paration is examined as quickly as possible. By this simple method the 
micro-organisms are stained a deep red, and many retain their mobility 
for a short time. At one of the poles the delicate corkscrewy or wavy 
flagellum can be perceived ; it is of a pale red hue and contains deeply 
stained granules in the long axis of the flagellum. Even in the motion- 
less organisms the flagellum can be seen, although it is less distinct. 
In the preparation can also be observed a number of free or detached 
flagella in active motion. The author only succeeded in staining by 
this procedure the flagella of the bacteria mentioned. 
Staining Tubercle Bacilli in Tissues.§ — For demonstrating tubercle 
bacilli in tissues Sig. G. Pacinotti hardens the material in Muller’s fluid 
and not in alcohol. The piece to be frozen should not be thicker than 
4 mm., but its other dimensions may be of any size. The sections should 
* Anat. Anzeig., viii. (1893) pp. 647-8 (1 fig.). 
f Arch. Sci. Phys. et Nat. Geneve, xxix. (1893) pp. 100-1. See Zeitschr. f. wiss. 
Mikr., x. (1893) p. 267. 
X Bull. Med., 1892, p. 1003. See Centralbl. f. Bakteriol. u. Parasitenk., xiv. 
(1893) p. 257. 
§ Gazzetta degli Ospitali, 1892, p. 726. See Centralbl. f. Bakteriol. u. Parasitenk., 
xiv. (1893) p. 292. 
