612 SUMMARY OF CURRENT RESEARCHES RELATING TO 



larvae. Groups of 20-30 isolated larvae were imbedded together, the 

 sections thus obtained being in a variety of planes. In order to de- 

 termine the direction of unorientated lavae, a set of standard sections 

 was prepared by carefully orientating single larvae which had been first 

 studied entire. 



To insure thorough impregnation of colonies with larvae in situ, the 

 material was left in xylol for about a week before being passed through 

 xylol-paraffin to paraffin. This material is difficult to imbed and section 

 owing to the presence of chitinous spines, which are sufficiently hard to 

 notch the razor. 



The most useful stain for sections was Heidenhain's iron-haema- 

 toxylin, followed by eosin in 90 p.c. alcohol. Other stains were used, 

 among which was Mayer's mucicarmin for detecting the presence of 

 mucin. 



Differentiation of Bacillus typhosus.* — Loeffier advocates the 

 following medium for the differentiation of the Bacillus typhosus. 

 100 c.cm. of distilled water containing 2 p.c. of peptone, and 1 p.c. of 

 nutrose, are neutralised by the addition of 1 • 06 c.cm. of normal potash; 

 to this is added 5 p.c. of lactose and 1 p.c. of glucose ; after boiling and 

 cooling, 3 c.cm. of a 2 p.c. solution of malachite green are added to the 

 mixture. When tubes of this medium are inoculated with Bacillus 

 typhosus, a coagulum is formed and a clear green liquid separates out ; 

 with other organisms, such as those of the Coli group, Bacillus enteriditis 

 Gaertner, and paratyphoid bacilli, active fermentation occurs, the pre- 

 cipitated nutrose adhering as dirty green flakes to the wall of the tube, 

 or carried to the surface of the liquid by the gas that is formed. When 

 glucose is omitted from the medium, only the Coli group cause a ferment- 

 ation. Other organisms have a reducing action on the green, turning it 

 a pale yellow colour. Paratyphoid A turns the liquid a pale blue colour. 



Ability of Vibrio choleras asiaticse to Decompose Starch.+ — M. H. 

 Gordon cultivated a series of bacteria in the following medium : Lemco 

 1 grin., peptone 1 grm., sodium bicarbonate 0*1 grm., starch 0*5 grin., 

 aqua dest. ad 100 c.cm. The medium is tinted with litmus. It has 

 been found that Vibrio cholera asiaticce, when cultivated in this medium 

 at 37° C, decomposes the starch with a strongly acid reaction within 

 24 hours, whereas the vibrio of Finkler and Prior produces no such 

 reaction in this time, and only a feeble acid reaction by the third day. 

 Staphylococci, streptococci, B. diphtheria, B. coli, B. enteriditis Gaertner, 

 B. typhosus, B. proteus, all fail to produce an acid reaction in this 

 medium. The rapid positive reaction of cholera, therefore, in this test 

 has a differential value. It may be added that the acid reaction notify- 

 ing decomposition of the starch is also produced by the cholera vibrio 

 when cultivated in distilled water tinted with litmus, and containing 

 1 p.c. peptone, ■ 5 p.c. salt, and 1 p.c. starch. 



Cultivating Wood-Destroying Moulds. 1 — B. Malenkovie finds that 

 the destruction of wood is due to the action of one or more different 



* Brit. Med. Journ. (1906) L, Epitome 328. See also Deutsch. Med. Woch., 

 Feb. 22, 1906. f Brit. Med. Journ., 1906, ii., p. 197. 



% Centralbl. Bakt., l te Abt. Orig., xli. (1906) p. 405. 



