74. SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 134 
Experimental vectors ——Blatta orientalis, Italy (Cao, 1898): Or- 
ganism passed unchanged through the gut with the feces and retained 
its virulence. 
Clostridium novyi (Migula) Bergey et al. 
or 
Clostridium sporogenes (Metchnikoff) Bergey et al. 
Synonymy.—‘Bacillo dell’edema maligno” of Cao. Steinhaus 
(1946) considered Cao’s organism to be C. sporogenes. Smith et al. 
(1948) stated that C. novyi was isolated in 1894 from guinea pigs 
with “malignant edema” and that it will probably never be settled 
whether C. sporogenes is identical with Koch’s bacillus of malignant 
edema. Obviously there is no way of properly identifying Cao’s 
bacillus of malignant edema. 
Source.—Gaseous gangrene; “malignant edema.’’ Habitat: Prob- 
ably manured soil. 
Natural and experimental vectors.—Blatta orientalis, Italy (Cao, 
1898) : Isolated from feces of naturally invaded cockroach. Experi- 
mentally the organism also passed unchanged through the gut with 
feces and retained its virulence. 
Clostridium perfringens (Veillon and Zuber) Holland 
Synonymy.—Clostridium welchit. 
Disease —Gaseous gangrene. Habitat: Feces, sewage, soil. 
Natural vectors—Cockroaches (presumably Blatta orientalis, 
Blattella germanica, and/or Periplaneta americana), Egypt (El-Kholy 
and Gohar, 1945): Isolated from whole suspensions of the cock- 
roaches. The organism that was isolated from the insects killed 
inoculated guinea pigs. 
Clostridium tetani (Fliigge) Holland 
Synonymy.—‘‘Bacillo del tetano” of Cao. 
Disease—Lockjaw or tetanus. Habitat: Soils, human and horse 
feces. 
Experimental vectors.—Blatta orientalis, Italy (Cao, 1898): Or- 
ganism passed through the gut unchanged in virulence, but the tetanus- 
toxin itself was destroyed in the intestine. 
Clostridium spp. 
Disease.—About half the derived species of Clostridium are patho- 
genic (Reed in Dubos, 1948). 
