502 < Scientific Proceedings (132) 



colonies may also be grown aerobically. Deep agar colonies are 

 distinctly larger, however, than those nearer the sufarce; there 

 is usually, but not always indeed, a distinct zone of inhibition 

 at and below the surface as with obligate anaerobes which is 

 hard to explain if this species is a facultative aerobe-anaerobe, as 

 my findings suggest. 



That the above observations, limited at first to a single strain, 

 were not to be interpreted as indicating acclimation of this strain 

 to aerobic life, was shown when three other French strains re- 

 ceived from Dr. Morton C. Kahn of Cornell University Medi- 

 cal School were also cultured aerobically. A fourth strain 

 labelled B. histolyticas by Major Jablons and received from Dr. 

 Kahn fail to grow aerobically and also failed to produce lesions 

 in guinea pigs. But a strain of B. histolyticas recently isolated 

 by my student, Miss Emelia Peterson, from a specimen of Cali- 

 fornia soil grows both aerobically and anaerobically and has been 

 transplanted aerobically three times with no apparent change in 

 morphology, cultural characteristics or virulence. 



247 (2207) 



The isolation of bacillus histolyticus from soil in California. 

 By EMELIA PETERSON and IVAN C. HALL. 



[From the Department of Bacteriology and Experimental Path- 

 ology, University of California, Berkeley, California.] 



During a survey of California soils for anaerobic bacteria, we 

 encountered a strain of B. histolyticas which is of interest as the 

 first recovery of this species in America and one of the few 

 records of its occurrence in soil. All of the other cultures so far 

 described came from war wounds in France and the only re- 

 corded proof of this organism as an inhabitant of soil, aside 

 from the fact that most war wounds are contaminated by dirt, 

 is a statement by the Medical Research Committee 1 that, "it 

 . . . has been obtained from earth." 



The soil specimen was a clay adobe from near Walnut Creek, 

 California, which lies in a rich agricultural valley of the coast 

 range about 12 miles from Berkeley. 



'British Medical Research Committee, Report No. 39, 1919. 



