ZOOLOGY AND BOTANY, M1CKOSCOPY, ETC. 93 



Influence of Symbiosis on the Virulence of Pathogenic Microbes.* 

 E. Klein finds that a culture of B. typhosus, which, in a certain dose, is 

 not capable of living and multiplying in the peritoneal cavity of a 

 guinea-pig, can be made to grow there, and to act virulently, if it be 

 introduced into the animal symbiotically with either B. enteriditis of 

 Gaertner, B. coli from ice cream, B. enteriditis sporogenes, or B. carnis ; 

 that Vibrio cholerce has its vitality and virulence enhanced by symbiotic 

 introduction into a guinea-pig with B. <oli from ice cream, or with B. 

 carnis ; and that a similar enhancing influence is exerted on B. diph- 

 theria by Streptococcus pyogenes. 



Loss of Nitrogen in Soils.f — P. Ehrenberg inoculated 100 c.cm. of 

 pepton solution with 10 c.cm. of soils obtained from various sources. 

 The flasks were incubated at 80° C. for eight days ; the solutions were 

 then filtered and the total nitrogen content compared with that of the 

 inoculated solution before incubation. He finds that the apparent loss 

 of nitrogen by the putrefaction of the pepton solution inoculated with 

 soil, is explained rather as an absorptive action than as a biological con- 

 sumption of the nitrogen. 



Klein, E. — Vitality of the Typhoid Bacillus in Shell-fish. 



Trans. Pathol. Soc, lvi. (1905) pp. 231-8. 



* Local Gov. Board Med. Officer's Rep., 1903-4, Supp., p. 431. 

 t Centralbl. Bakt., 2* Abt., xv. (1905) p. 154. 



