ZOOLOGY AND BOTANY, MICROSCOPY, ETC. » 527 



of alcohol, but if understated it should be dehydrated iu anilin oil-xylol 

 in equal proj>ortions. Kresylecht violet is a good stain for amyloid, 

 plasma-cells, blood-preparations, and malarial parasites. 



Sudan iii. Stain for Tubercle Bacilli.* — Dr. D. M. Cowie finds 

 that Sudan iii., recommended by Dorset f as a selective stain for the 

 tubercle bacillus, is a failure, and this experience is corroborated by 

 Dr. Le Doux | of Grahamstown, South Africa, who states that his results 

 are also negative. 



Staining of Ligneous Tissue. § — M. J. Chalon gives the following 

 resume of the staining reactions of ligneous tissue after treating the 

 sections with aqueous or alcoholic solutions of the reagents followed by 

 sulphuric acid. 



Phloroglucin (in this case hydrochloric acid should be substituted 

 for sulphuric) : the colour is a bright rose, lasting often 12 hours or more. 

 Carbazol : red-violet. Orcine : red, passing to violet. Resorcin : pale 

 violet blue. Naphthol A : yellow, passing to pale green. Pyrogallic 

 acid : bronze-green. Indol : red. 



(5) Mounting 1 , including- Slides, Preservative Fluids, &c. 



Formalin and Alcohol as Preservatives for Zoological Specimens. || 

 — Mr. J. Hornell, in discussing the respective values of formalin and 

 alcohol as preservatives for museum specimens, expresses the opinion 

 that the best effects of formalin are seen with Medusas and Tunicata. 

 Most animals should be mounted in formalin-alcohol after previous 

 fixation. For some animals which contain lime salts, such as echino- 

 derms and crustaceans, formalin is unsuitable, as it slowly decalcifies 

 them and renders them very brittle. 



In collecting trips formalin is more useful than alcohol, as in its 

 concentrated form it does not occupy so much space, and is therefore 

 more easily stowed. In microscopical technique, maceration of the 

 objects, sections, &c, may be obviated by the use of a 2 per cent, solution, 

 either as an addition to staining solutions, or to replace pure water in 

 washing out fixatives. 



Easy Method of Mounting and Preserving Mosquitos.f — Mr. D. 

 C. Rice describes the following method adopted in the London School 

 of Tropical Medicine for mounting mosquitos. All that is required 

 are slides, round cover-glasses, glass rings about 1/16 to 1/12 in. 

 deep and 7/8 in. in diameter, and xylol Canada balsam. Kill the 

 mosquito by placing in an ordinary killing bottle, or if this is not avail- 

 able, a little chloroform or tobacco smoke will do as well ; when dead 

 turn it over on its back, separate the legs if they are together, place a 

 large drop of thick xylol Canada balsam on a slide, invert this gently 

 on to the mosquito, and in this way it is picked up without any chance 

 of injury ; then with a fine needle spread out and arrange the wings and 

 legs, and if necessary press down the thorax very carefully. Next pour 

 on some thin xylol Canada balsam ; as this runs out it straightens the 



* New York Med. Journ., lxxi. (1900) pp. 16-7. 



t Of. this Journal, 1899, p. 236. 



1 Centralbl. Bakt. u. Par.. l t0 Abt., xxvii. (1900) p. 616. 



§ Bull. Soc. Beige Micr., xxv. (1898-9) pp. 106-7. 



|| Laboratorium et Museum, 1900, pp. 85-9. 



\ Brit. Med. Journ., 1900, i. p. 1468. 



2 n 2 



