392 The Philippine Journal of Science 1915 
charged with the feces, it is easy to conceive how these small 
flies, when feeding thereon, can disseminate infections by the 
carriage of bacteria either upon the surface of their bodies or 
contained within their intestinal tracts. As they are omnivorous . 
feeders when they enter homes, they may either contaminate 
food upon which they feed or become a source of danger by being 
ingested with the food. 
Special emphasis is laid upon their minute size, as they can 
pass through the ordinary so-called fly-proof screen with great 
ease. Entrance may be gained through very small apertures 
or cracks into food-containing vessels, and the fly imprisoned and 
killed therein. Pails or chambers which are used for the deposit 
of human feces, although safe against the common house fly, are 
by no means safe against the ingress of these very minute inseets. 
Aphiocheta ferruginea Brunetti is a very common species in 
the Philippines. As this species has been reported as producing 
intestinal myiasis in man, a field of speculation is opened of grave 
importance, should this prove to be of commoner occurrence than 
has been reported. Cases of intestinal myiasis may readily be 
overlooked, by regarding the larve or eggs as being deposited in 
the feeces after they have been passed. Adult flies may be passed 
per rectum and fly away and not be seen. 
Should myiasis occur in a case of cholera, and adult flies be 
discharged, dissemination would occur by means of these cholera- 
drenched flies. 
Before too much significance is attached to the Phoride as 
porters or carriers of bacterial infection, certain facts must be 
established by experimentation regarding them. 
In the experiments outlined in this paper Aphiocheta ferru- 
ginea was chosen for the following reasons: (1) Its great fre- 
quency as a breeder in human feces. (2) When once determined 
it ean readily be recognized. (8) It is a trifle larger than the 
other members of the family and can be handled with less dif- 
ficulty. (4) No experimental work has been performed on this 
species since it was discovered. (5) Facts ascertained concern- 
ing this species will open a field of investigation appertaining 
to the entire family, of which very little is known. 
The object in view is to establish the following facts: 
1. Whether or not cholera vibrios are harbored during the 
chrysalis stage. 
2. Is infection transmitted from the chrysalis stage to the 
imago? 
3. Do adult flies, when fed on cholera vibrios, harbor these 
