ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 257 



New Triple Stain.* — Dr. A. Pappenheim has devised a new tri- 

 acid stain, the basis of which is Unna's polychrome methylen-blue. It 

 is apparently useful for staining blood-films. It gives three colours, 

 red, blue, yellow, in various shades, and hence has a selective action. 

 The stain is made by Grubler, and cau be obtained in aqueous solution 

 or in powder. 



Staining the Capsule of Anthrax.f — Kiibiger treats air-dried films 

 of anthrax with a solution of 15-20 gentian-violet to 150 formaldehyde, 

 thus simultaneously fixing and staining the preparation. The time 

 required is about 20 seconds, after which the preparation is washed with 

 water and examined. 



(6) Miscellaneous. 



Microtechnique of Animal Morphology.! — The second portion § of 

 Prof. S. Apathy's work on the microtechnique of animal morphology 

 has recently appeared. It contains the sections E, F, G, of which the 

 first deals with methods for more closely appreciating the microscopic 

 pictures of living objects, their measurement, and representation by 

 photomicrography. The second treats of the methods of illuminating 

 preparations by non-polarised light, while section G reviews the methods 

 of illumination with polarised light for biological purposes, and the 

 methods for determining the refractivity of microscopic objects. The 

 facts, which are arranged in chronological sequence, are positively 

 astounding in number, and their mere enumeration tells of the extra- 

 ordinary labour which the author has bestowed on the work, and the 

 knowledge of the subject exhibited therein. 



Distinguishing between Pleurosigma angulatum and balticum 

 under Low Powers. || — According to G. Marpmann, Pleurosigma angii' 

 latum and PI. balticum can be discriminated by low powers and direct 

 illumination, the former being greenish-yellow, the latter yellowish- 

 brown. With dark -ground illumination the valves of PL balticum pass 

 through blue, green, yellow, to red on the dark blue ground, while the 

 colours of PL angulatum only come out later. Some of the discoid 

 species exhibit analogous phenomena when examined under similar con- 

 ditions. 



Gelatin as a Substitute for Glass. If — G. Schneider mentions, in 

 connection with Pranter's suggestion of gelatin cover-slips, that gelatin 

 capsules, such as are used by chemists, are very convenient for keeping 

 specimens in, and for sending them by post, &c. The tubes are filled 

 with a solution of formalin, or with 70 p.c. alcohol, and after inserting 

 the specimen along with a ticket, are closed with another gelatin tube, 

 which is slipped over it. Several of these tubes may be placed, for 

 preservation or transport, in a large vessel filled with formalin solution 



* Deutsch. Med. Wochenschr., No. 46. See Zeitschr. angew. Mikr., vii. (1901) 

 pp. 237-40. 



t Zeitschr. f. Fleisch- u. Milchhyg., xi. No. 3. See Centralbl. Bakt., 1" Abt, 

 xxx. (1901) p. 937. 



% Die Mikrotechnik der thierischen Morphologie, 2nd part, Leipzig, 1901, 

 pp. 321-60. § See this Journal, 1896, p. 690. 



|| Zeitschr. angew. Mikr., vii. (1902) pp. 253-4. 



«| Zeitschr. wiss. Mikr., xviii. (1902) pp. 288-90. 



April 16th, 1902 s 



