394 
C. GORDOX HEWITT. 
of cleaning' themselves, after which they were allowed to walk 
over the films of media. Although we were unable to recover 
B. typhosus the pi'esence of B. coli was demonstrated. 
B. coli was also obtained from flies obtained on a public tip 
upon which the contents of pail-closets had been emptied; the 
presence of B. coli, however, may not necessarily indicate 
recent contamination with human excrement. Aldridge (1 . c .) 
isolated a bacillus apparently belonging to the paratyphoid 
group from flies caught in a barrack latrine in India during 
an outbreak of enteric fever. In appearance and behaviour 
to tests it was very similar to B. typhosus. 
Although we ai’e not certain yet as to the specific organism 
or organisms which cause the intestinal disease known as 
infantile or summer diarrhoea, which is so prevalent during 
the summer months and is responsible for so great a mortality 
among young children, I think we must consider the relation- 
ship of ]\] . domestica and its ally Homalomyia cani- 
cularis to this disease epidemiologically similar to typhoid 
fever. 
2. Anthrax. 
In considering the relation of flies to anthrax several facts 
should be borne in mind. As early as the eighteenth century 
it was believed that anthrax might result from the bite of a 
fly, and the idea has been used by Murger in his romance 
' Le Sabot Bouge.’ A very complete historical account of 
this is given by Nuttall (1899). Most of the instances in 
support of this belief, however, that flies may carry the 
infection of anthrax, refer to biting flies. As I have already 
pointed out, M. domestica and such of its allies as H. 
canicular is, C. erythrocephala, C. vo mi tori a, and 
Lucilia csesar are not biting or blood-sucking flies. The 
nearest allies of i\I. domestica which suck blood in England 
are S. calcitrans, Hsematobia stimulans Meigen, and 
Lyperosia irritans L. ; the rest of the blood-sucking flies 
which may be considered in this connection belong to the 
family Tabanidm, including the common genera H£ema- 
