ENTOMOLOGY

386 SA.NITARY ENTOMOLOGYfind that it acquired. pathogenicity by passage through the intestines ofthe insect with or without other foods.Bacillus "proteisimile" Cao. An organism virtually described underthis name was isolated by Caa from the feces of Blatta orientalis in two ormore series of experiments in three different strains of varying virulence.One strain retained its virulence in successive passages for five months. Intwo experiments in which starved cockroaches with nonpathogenic feceswere fed on nonvirulent· cultures of this germ and on a diet of breadwith putrid infusion of beef liver, and on a diet of 1 per cent infusionof peptone, this germ became. intensely pathogenic' in the first case., killing,when inoculated, a guinea pig in two or three days, and in the second casein 36 to 40 hours, with acute septicemia. 0Bacillus "pseudo edema maligno" Cao, cause of MALIGNANTPSEUDOEDEMA, was isolated by Co.o in one instance from a series ofB. orientalis, and he found it retaining its virulence in successive passagesthrough many months.Bacillus radiciformis Tataroff, a saprophytic organism found in water,was isolated by Co.o from the feces of Blatta orientalis in a single seriesof experiments. In all of his tests with this organism, he did not findthat it acquired pathogenicity by passage through the intestines of theinsect with or without other fvods.Bacillus "similcarbonchio" Cao, an organism described by Cao as similarto B. anthracis, was isolated in pathogenic strains from Blattaorientalis by Cao. In one series of experiments it was isolated from anumber of B. orientalis, the feces of which, when inoculated into a guineapig, caused its death in 42 hours. From pure cultures isolated from thefeces, it was inoculated into a guinea pig and caused its death in 40 hours,with intense sero-sanguinolent edema and an enormous spleen. The organismwas recovered from the heart blood. A cony inoculated with pureculture died in 48 hours, with symptoms similar to those found in hematiccarbuncle. The germs were still found in the feces of the cockroachesafter 21 days fasting and retained their virulence, causing death withformation of a tumor on the spleen, but less intense. It maintained itsvirulence in successive' passages through many months. When fed tostarved cockroaches with nonpathogenic feces, two nonpathogenic strains(one from soil and one from the feces of Calliphora 'tJomitoria) failed toincrease their pathogenicity when eaten alone, or when combined withsterile bread, sour milk, putrid milk, rotten egg, and fresh flesh; but onestrain obtained slight pathogenicity when eaten with putrid flesh, moderatepathogenicity when combined with human feces, and intense pathogenicitywhen eaten with 00. diet of bread and putrid beef liver, a diet of breadand 1 per cent infusion of peptone, or a diet of bread and an infusion ofputrid beef flesh.