ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 729 



Value of Malachite-green Medium for Differentiating B. typhosus 

 and B. coli.* — G-. Kiralyfi bus made ;i number of observaions of tmlti- 

 vating bacteria on media containing malachite-green, and from these 



he concludes that the addition of this material does undoubtedly binder 

 and stop the. growth of many micro-organisms, such as streptococci, 

 staphylococci, II. anthracis, \'ibrio cholrrm, etc., but for the purpose 

 of differentiating B. typhosus and B. coli, it is irregular and quite 

 unreliable. 



Cultivation of Microbes in Media of Definite Chemical Com- 

 position.! — J- Gralimard, L. Lacomme, and A. Morel obtain acid amides 

 from the hydrolysis of various albumens, and these are then added 

 either separately or mixed together, in proportion of 1 to 2 p.c. to 

 bouillon composed of sodium chloride 0'5 grm., sulphate of magnesium 

 0'05 grm., glycerophosphate of calcium 0'2-0'3 grm., bicarbonate of 

 potash to produce a slight alkalinity, glycerin 1 • 5 grm., and water 

 100 grm. The whole is sterilised at 120° C. for 45 minutes. The 

 different media thus obtained from the various albumens are then 

 inoculated with B. pyocyamus, B. prodigiosus, B. coli R 2, and pneumo- 

 bacillus of Friedlander, etc. 



Cultivation of Bacillus typhosus from the Blood by means of 

 Bile Culture Medium. J — H. Conradi places a mixture of one part of 

 blood from a typhoid patient and two parts of sterilised ox-bile in an 

 incubator for 16 hours, after which varying amounts of the mixture are 

 transferred to litmus-lactose-agar. An addition of 10 p.c. of pepton to 

 the bile encourages the growth of B. typhosus, and better results are 

 obtained by an addition of 10 p.c. of glycerin which hinders the develop- 

 ment of saprophytes. The principle of this medium depends on the fact 

 that whereas ■ 3 c.cm. of normal guinea-pig serum in dilution of 1 in 80 

 will kill 20,000 typhoid bacilli within two hours, after the addition of 

 1-0 • 1 c.cm. of bile to the same normal guinea-pig serum, the bacteri- 

 cidal serum action is no longer observed. The author claims that this 

 method may be readily used by general practitioners and clinicians, and 

 he describes its practical application. It is further claimed that after 

 30 hours it is possible to establish with certainty a typhoid diagnosis. 



(2) Preparing- Objects. 



Studying the Tympanal Apparatus of Orthoptera.§ — J. Schwabe 

 begins his description with the remark that he has had no trouble with 

 the chitin, and has made perfect series of sections. He begins by re- 

 moving quickly all superfluous parts, and then getting the material into 

 paraffin as rapidly as possible. The prolonged use of alcohol must be 

 avoided, as it obscures the histological details and also makes the chitin 

 so brittle that it cracks like glass when cut. Each section should be 

 picked up with a brush. The use of eau-de-Javelle, eau-de-Labarraque, 

 or hot potash is deprecated. The difficulty of fastening sections of 



* Centralbl. Bakt., lte Abt. Orig. xlii. (1906) p. 371. 



t Comptes Rendus, cxliii. (1906) p. 349. 



% Centralbl. Bakt., He Abt. Orig., xxxviii. (1906) p. 55. 



§ Zoologica, xx. (1906) pp. 3-5. 



