ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 375 



on to E (avoiding any passing into C), half being allowed to filter into 

 F, and half into G ; F and G are then clamped and separated from the 

 apparatus. The mycelium in A is now broken up by the rod B, water 

 is added, and the washing passed on from A into F' and G' through 

 the cork E. 



Structure of Rhizobium Leguminosarum.* — R. Greig Smith, for 

 the structural examination of this organism, advises the growing of large 

 cells by use of agar containing maltose, citrate and sulphate of ammonium ; 

 and staining with fuchsin O'l grm., alcohol 10 c.cm., 1 p.c. phenol 

 90 c.cm. Add a loopful of slime to 4 c.cm. of distilled water in a test- 

 tube warmed to 80° C. in water-bath ; the slime is distributed in the 

 water and a uniform suspension of the cells obtained : 2 c.cm. of the 

 stain, at 80° C, is added, and the test-tube is kept at 80° C. for 4-8 

 hours. A drop of the suspension is then spread on a coverslip, dried in 

 air, flamed, decolorised with 0'5 p.c. acetic acid, dried again, and 

 mounted. When properly stained the rods are seen as bipolar staining 

 spherules. 



Action of Particulate Conditions on Microbic Cultures.f — 

 P. Harckman inoculated with 1 c.cm. of well water each of three Petri 

 dishes, containing respectively gelatin dissolved in pure water, gelatin 

 dissolved in a solution holding particles of tin, and gelatin dissolved in 

 a solution holding particles of leather. The gelatin and tin culture 

 showed numerous vigorous colonies after four days, the medium being 

 completely liquefied after fourteen days ; the gelatin and leather culture 

 manifested no growth within four days, and the gelatin and pure water 

 showed only a few scarcely perceptible pin-point colonies. The colonies 

 on the medium containing tin had the yellow colour of sulphide of tin 

 and later the violet of oxide of tin. The author concludes that particles 

 of tin are exciters to microbial growth ; he found that manganese was 

 also an exciter, but to a less degree than tin. The phenomenon is 

 represented diagrammatically ; regarding the living organism as positively 

 electrified, and the particles of tin as negatively electrified, the excita- 

 tion resulting from the induction of negative ions on the positive ions 

 determines the excitation which governs the production of vital pheno- 

 mena. The contrary effect results when ttie particulate ions have a 

 positive polarity, as in the case of leather. 



Detection of Bacillus typhosus. J — 1. Cultivation of B. typhosus 

 from the blood by means of bile medium. H. Conradi recommends the 

 following method for use by medical practitioners : • 5 c.cm. of blood 

 is taken from the lobe of the ear, mixed with 10 c.cm. of sterihsed ox 

 bile, and added to 10 parts of pepton and 10 parts of glycerin contained 

 in an easily sterilised glass tube closed by a glass stopper ; this is in- 

 closed in a wooden case and sent to a bacteriological institute. There 

 the tube is incubated at ?>7°C.for 16 hours, when subcultures should be 

 made on litmus-lactose-agar. After iiO hours the diagnosis of typhoid 

 is estabhshed. 



* Proc. Linn. Soc. N.S.W., 1906, p. 295 (2 pis.), 

 t Bull. Classe des Sci., 1906, No. 5, p. 335. 

 X Centralbl. Bakt., Ref., xxxix. (1907) p. 395. 



