ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
277 
Simultaneous Double Stain for Leprosy and Tubercle Bacilli.* — 
Dr. P. G. Unna describes a new method of staining leprosy and tubercle 
bacilli with polychrome methylen-blue, a pigment which must be obtainod 
from Griibler. The method resulted from tho observation that somo 
sorts of methylen-blue contained methylen-red as well. By adding 
alkaline carbonates the red hue was found to be greatly improved, and it 
is well differentiated by acids, but still better by saturated aqueous tannin 
solution. The sections are stained for ten minutes to some hours in 
polychrome methylen-blue solution. On removal they are washed in 
water and then differentiated by immersion in 33 per cent, tannin solu- 
tion. They are again washed in water and then dehydrated in absolute 
alcohol, cleared up in bergamot oil, and mounted in balsam. 
After removal from the tannin solution, and having been carefully 
washed, the process may be varied as follows : immersion in spirituous 
gold-orange solution or 25 per cent, nitric acid ; then dilute spirit, water, 
absolute alcohol, bergamot oil, balsam. 
Staining-differences of Male and Female Cells.f — According to 
Dr. v. Raciborski, these differences, while well displayed in all higher 
plants, are wanting in many of the Coniferse. This author has come to 
the conclusion that even in the higher plants there is no essential differ- 
ence between the male and female nuclei, and that their staining 
phenomena present no argument against the theory of impregnation 
propounded by Hertwig, Strasburger, and Boveri. 
C 5) Mounting 1 , including: Slides, Preservative Fluids, &c- 
Preservative Fluid for Animals.f — M. Wiese (sic) is reported to 
recommend the following fluid for preserving the bodies of animals in 
their natural form and colours. 600 grm. of hyposulphite of soda are 
dissolved in 5 litres of water, and 75 grm. of chloride of ammonia in 
250 grm. of water. The two solutions are mixed, and 4 to 6 litres of 
spirits of wine added. 
Formaldehyde for Hardening and Preserving.§ — Dr. F. Blum 
calls attention to the importance of formaldehyde (formol) as a reagent 
which does not affect the transparency of the tissues, does not preci- 
pitate mucin, often allows the natural colours to persist, and causes 
no shrinkage. He refers to his father’s use of this fluid in preserving 
eyes, || and criticizes a recent communication by Hermann.^ Formol 
is a 40 per cent, solution of formaldehyde, and the hardening fluid is 
formol diluted ten times with water. 
Microscopical Preparations of Algse.** — M. A. Lemaire recommends 
the following process for permanent preparations of green algae. Fix in 
a saturated solution of uranium acetate with 0 • 3 per cent, chrome-alum ; 
leave for from 6-12 hours in the solution, and then wash thoroughly ; 
place on the slide in 2 or 3 drops of a 10 per cent, solution of glycerin ; 
* Monatshefte f. prakt. Dermatol., xvi. (1893) pp. 399-403. 
t SB. Bot. Ver. Miinchen, Jan. 8, 1894. See Bot. Centralbl., lvii. (1894) p. 168. 
t Rev. Scientif., 1893, p. 543. See Bull. Soc. Zool. France, xviii. (1893) 
pp. 211 and 2. § Anat. Anzeig., ix. (1894) pp. 229-31. 
|| Zool. Anzeig., 1893, No. 434. Anat. Anzeig., ix. No. 4. 
** Journ. de Bot. (Morot), vii. (1893) pp. 434-40. 
