ZOOLOGY A.ND BOTANY, MICROSCOPY, ETC. 629 



to the action of radium for periods varying from 10 to 60 minutes. In 

 every case the authors found there was no alteration in the capacity for 

 growth, staining reaction, colour production, or motility. It was, how- 

 ever, noted that there was a slight increase in motility of B. typhosus 

 after 15 minutes' exposure, but not so after 30 to 60 minutes' exposure. 



Bacteria in the Air.* — K. Saito exposed Petri plates with various 

 nutrient media, for one minute to the air in different situations, and at 

 different times of day, and made observations of the number and 

 variety of bacterial colonies that grew. The author found that in the 

 ah' of the botanical gardens, the average maximum number of colonies 

 appeared in November, the average minimum in September ; the air of 

 various streets gave a fewer number than the garden air ; generally, 

 organisms were found to be more numerous in warm and dry than in 

 cold and moist seasons ; the numbers are increased by wind ; after rain 

 and snow the air holds very few bacteria. In the course of his research 

 the author isolated 55 varieties of bacilli and 17 varieties of cocci, of 

 which one, Sarcina agilis, was a new species. 



Biological Study of Glanders Bacilli.f— W. Stickdorn finds that 

 the virulence of glanders bacilli is lowered by prolonged cultivation on 

 nutrient media ; after passing through white mice the virulence for 

 white mice is maintained, but it is lowered for grey mice ; passage 

 through pigeons assists the virulence for pigeons, but raises the virulence 

 for grey mice. 



Cultural Differences of two Pseudo-tubercle Bacilli.! — L. Vin- 

 cenzi contrasts the Bacillo opale agliaceo, a pseudo-tubercle bacillus 

 having a blue coloured growth on gelatin, and a strong odour of 

 garlic, with a bacillus of Pfeiffer. Both organisms are non-motile, 

 round-ended rods with capsules, arranged in chains, not producing 

 spores, and being potential anaerobes ; they both grow on all ordinary 

 media, but B. opale agliaceo grows at 0° C, whereas the minimum tem- 

 perature for Pfeiffer's bacillus is 5°C. The growths on gelatin are 

 similar, but that of B. opale is paler and has a blue tint ; that of Pfeiffer's 

 bacillus is pale yellow, and has a mottled appearance ; colonies of 

 B. opale are moist and shining, those of Pfeiffer's bacillus are dry ; in 

 gelatin streak cultures the growth of B. opale is thin, opalescent, and 

 moist ; that of Pfeiffer's bacillus is thick, whitish-yellow, and dry ; both 

 organisms are pathogenic for guinea-pigs and rabbits, but B. opale has 

 a higher degree of virulence. 



Chromogenic Bacillus isolated from a Mineral Water. § — 

 L. Gaucher isolated from Vals water an actively motile, pigment- 

 forming bacillus. It is about 7-8 /x long and 1 ^ broad ; it is easily 

 stained, but is Gram-negative. Its optimum temperature is 20° C. ; it 

 it a potential anaerobe, but does not form pigment without access of 

 air ; it forms acid, and liquefies gelatin slightly. The colonies attained 



* Journ. Coll. Sci. Imp. Univ. Tokyo, xxiii. art. 15. 



t Centralbl. Bakt., lte Abt. Orig. 1. (1909) p. 5. J Tom. cit., p. 2. 



§ C.R. Soc. Biol. Paris, lxvi. (1909) pp. 745-6. 



Oct. 20th, 1909 2 u 



