402 
C. GORDON HEWITT. 
In two oE the experiments the flies were all dead on the 
seventh and eighth days respectively, at a temperature of 
14° 0. At higher temperatures he found that flies died more 
lapidly. He was able to show that the flies contained the 
bacilli in a virulent condition for about two days after thej’’ 
had fed on infected organs ; this,, and the fact that the infected 
flies can live for several days, are extremely important from 
the practical standpoint, as indicating that flies should neither 
be allowed to have access to the bodies or excreta of cases of 
plague, nor to the food. 
7. Miscellanea. 
There are on record a number of suggestions that flies may 
be responsible for the dissemination of other diseases caused 
by bacteria and other micro-organisms, and some account will 
now be given of these and the experiments in support of such 
beliefs. 
If flies have access to wounds of an inflammatory and sup- 
purative nature they are liable to transport the kStaphylo- 
cocci to other spots. Buchanan (1907) allowed M. domestica 
to walk over a Him of Staphylococcus pyogenes aureus 
from an abscess, and afterwards over agar ; a mixed growth 
resulted, in which S. pyogenes aureus predominated. 
Celli (l.c.) records experiments which proved that S. 
pyogenes aureus retains its virulence after passing- 
through the intestine of the fly. 
In the experiments carried out in 1907 by my friend Dr. 
M. B. Arnold and myself, he chose B. prodigiosus for 
the purposes of the experiment, as it is easily recognisable 
and not likely to be accidentally introduced. Flies which had 
just emerged from the pupae, and therefore not already con- 
taminated with an extensive bacterial flora, were allowed to 
walk over a film of the bacillus, after which they were con- 
fined to sterile glass tubes. At varying periods they were 
taken out and allowed to walk over the culture plates. Those 
confined for over twelve hours retained the bacilli on their 
