NO. 10 COCKROACHES—ROTH AND WILLIS 59 
(1948), and Smith et al. (1948), streptococci like the above would 
probably fall in the viridans group. 
Disease.—Streptococci of the viridans group occur in pus, abscesses, 
and in the human mouth, throat, and nasopharynx. 
Experimental vectors.—Blatta orientalis, Germany (Jettmar, 
1935) : Organism isolated from the hindgut and feces in almost pure 
culture. A mouse was successfully infected through subcutaneous 
injection, 
Streptococcus spp. 
Disease—Some species of Streptococcus are highly pathogenic, 
and for that reason these undetermined species are listed here. 
Natural vectors.—Blatta orientalis, Germany (Jettmar, 1935): 
Cultures from the hindgut contained short chains of streptococci. 
Blattella germanica, U.S.A. (Janssen and Wedberg, 1952) : Organ- 
ism isolated from the feces and alimentary canal. Germany (Jettmar, 
1935): I9 specimens, captured in the operating room of a hospital, 
were found to be externally contaminated with streptococci which pro- 
duced green colonies on blood agar. ; 
Cockroaches, U.S.A. (Longfellow, 1913): A streptococcus that 
hemolyzed human blood was isolated from the insects’ viscera. 
Experimental vectors.—Blatta orientalis, Italy (Cao, 1898): The 
streptococci did not pass through the gut of this insect after an in- 
fective feeding. 
Family CORYNEBACTERIACEAE 
Corynebacterium diphtheriae (Fliigge) Lehmann and Neumann 
Synonymy.—“Bacillus Klebs-Loeffler” of Longfellow; “Bacillo di 
Loffler” of Cao. 
Disease.—Diphtheria in man. 
Experimental vectors.—Blatta orientalis, Italy (Cao, 1898): Or- 
ganism could not be recovered from the feces. 
Cockroaches, U.S.A. (Longfellow, 1913): Organism recovered 
from legs of cockroaches exposed to sterile food that Longfellow had 
inoculated with C. diphtheriae. 
Family ENTEROBACTERIACEAE 
Escherichia coli (Migula) Castellani and Chalmers 
Synonymy.—Bacillus coli; B. coli commums ; Bacterium coli. 
Disease.—Causes infections of genitourinary tract. Invades circu- 
