NO. 10 COCKROACHES—ROTH AND WILLIS 63 
the fourth day. In the insects’ intestinal canals, the organism changed 
under influence of the host, but after it was subcultured or passed 
through mice, the modified strain regained its original properties. 
Blattella germanica, U.S.A. (Olson and Rueger, 1950; T. A. Olson, 
p.c.): The organism was recovered from the feces within 2 days 
after feeding. U.S.S.R. (Rozengolts and [udina in Pavlovskii, 1948) : 
See comments under B. orientalis. 
Polyphaga saussurei, U.S.S.R. (Zmeev in Pavlovskii, 1948): The 
organism was fed in bread and human feces; it passed through the 
cockroach unchanged. 
Salmonella morbificans (Migula) Haupt 
Synonymy.—Salmonella bovis-morbificans. 
Disease.—Gastroenteritis, septicemia in cattle. 
Natural vectors —Periplaneta americana, Australia (Mackerras and 
Mackerras, 1948): This record may have included Periplaneta ignota 
which was not recognized at that time as distinct from P. americana 
(Mackerras and Pope, 1948). Organism isolated from the guts of 
cockroaches captured in hospital wards in which cases of gastroenteri- 
tis were occurring. During the epidemic, there were three invasions 
in 16 cockroaches collected in childrens’ wards, but none in 146 cock- 
roaches from other hospitals or outside in the same period, or in flies 
(Mackerras and Mackerras, 1949). Dr. I. M. Mackerras (p.c.) has 
confirmed that the isolations attributed to “‘cockroaches” in the 1949 
paper are the same as those that were reported for P. americana in 
the 1948 paper. 
Experimental vectors.—Nauphoeta cinerea, Periplaneta australasiae 
Periplaneta ignota, and Supella supellectilium, Australia (Mackerras 
and Pope, 1948): All the above cockroaches were invaded by this 
organism after feeding on sucrose broth cultures. Isolation of the 
organism was made from the feces or guts after death. The longest 
period of infection was 19 days, in P. ignota. 
Salmonella paratyphi (Kayser) Castellani and Chalmers 
Synonymy.—‘Paratifa A” of Pavlovskii. 
Disease.—Enteric fever in man. 
Experimental vectors.—Polyphaga saussurei, U.S.S.R. (Zmeev in 
Pavlovskii, 1948): The organism, when fed in bread and human 
feces, passed through the insect unchanged. 
