ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 307 



two very narrow ones in tlie wall whicli separates two contiguous cortical 

 cells, but tlie author has not seen them on the walls which separate cells 

 from aeriferous canals. The observation is rendered easier by immersion 

 for some moments in hsematoxylin dissolved in alcohol ; the protoplasm 

 preserves the rose-colour given to it by the eosin ; the cellulose swells 

 and becomes light violet, and the cuticular coatings, the corners, and the 

 median lamellae are coloured dark violet. 



Red Stain for Vegetable Sections.* — Dr. F. L. James says that 

 a beautiful red stain for vegetable sections may be extracted from the 

 parings of wine-sap and other red apples, by absolute alcohol. The 

 paring of a single medium-sized apple gives about 1 drachm of a very 

 deep ruby-coloured solution. The author has experimented but little 

 with the stain, but can say that it is apparently stable. 



Staining Bacilli of Rhinoscleroma.t — Dr. G. Melle advises the 

 following new method for staining the bacillus of bhinoscleroma. The 

 sections are stained for 10-15 minutes in gentian-violet (2 parts gentian 

 violet, 15 alcohol, 100 water), they are then immersed for 2-3 minutes 

 in the iodine solution, and decolorized in absolute alcohol. Decolora- 

 tion is completed by placing the sections for 1-2 minutes in a 30-40 

 per cent, nitric acid, and afterwards again in alcohol. The sections are 

 next stained for 4 or 5 minutes in an aqueous solution of safranin. The 

 bacilli are stained violet, and the ground tissue of the cells, &e., red. 



By this method of staining the capsule environing the bacilli is not 

 seen, and these are found in collections of 10-40 within the cells. 



Injecting and Preparing the Circulatory System of Fishes.f — For 

 examining the circulatory system, says Dr. P. Mayer, injections are 

 requisite. As the removal of coagula from the vessels of fishes is 

 impossible, it is necessary to take special precautions. For killing the 

 animals the author recommends fresh water, or a strong solution of 

 potassium chloride in fresh water. Before the occurrence of rigor the 

 animal must be cut through close behind the anus, and injected with 

 distilled water or 10 per cent, alcohol. If the vessels be empty of blood 

 the tissues may be allowed to relax, and then injected with soluble 

 Berlin blue of the following composition: — 1. Liq. ferri perchlor., 

 10 ccm. ; aq., 500 ccm. 2. Ferrocyanide of potash, 23 g. ; aq,, 

 500 ccm. 



No- 1 solution is poured into No. 2, and left for 12 hours, the yellow 

 fluid is poured off, and the filtrate washed until it trickles through a 

 deep blue. About 1 litre of injection fluid is thus obtained, and this 

 will keep for about six months. As this gives a precipitate with salts 

 and with blood, the vessel must be well washed out. A slight addition 

 of acetic acid to the injection water is useful as in the presence of 

 alkalies Berlin blue loses colour. 



If a greater pressure than usual be required this may be obtained by 

 inserting a 10 litre glass vessel provided with a manometer, in which 

 the air can be compressed by means of a spray bellows. The caudal 

 vessels were injected through the aorta by means of a conical glass 

 cannula, and the superficial vessels from the venae laterales cutaneae. 

 The injection completed, the vessel is plugged with a glass cone, and 



* The Microscope, ix. (1889) p. 24; from ' National Druggist.' 

 t Resoconto d. Accad. Med.-Chi. di Napoli, 28 Aug., 1887. Monatschr. f. Prakt. 

 Dermatol., 1888, p. 82. J MT. Zool. Stat. Neapel, viii. (1888) p. 307. 



