HABITS OF THE ADULT FLY 
55 
he captured some 350 flies and marked each one’s wing 
or thorax with a small spot of gold enamel. Flies so 
marked were repeatedly observed about dwellings from 
twenty to forty rods from the barn up to the third day, 
but in a dwelling house a half mile away none of the 
marked specimens was detected. This, however, was a 
very unsatisfactory experiment, because it does not in 
the least show that if the dwellings twenty to forty 
rods from the barn had not existed flies would not have 
been found in the dwelling half a mile away. As Hine 
himself states, “It appears most likely that the dis¬ 
tance flies may travel to reach dwellings is controlled 
by circumstances. Almost any reasonable distance may 
be covered by a fly under compulsion to reach food or 
shelter. Where these are close at hand the insect is 
not compelled to go far, and consequently does not 
do so.” 
Hewitt is of the opinion that normally house flies 
do not fly great distances, and compares them to do¬ 
mestic pigeons which hover about a house in the im¬ 
mediate neighborhood. He states that they are able 
to fly, however, for a considerable distance and can be 
carried by the wind. At one time when he was vis¬ 
iting the Channel Islands he found the house fly from 
one and one-half to two miles from any house or any 
likely breeding place that he was able to find. He 
mentions some exact experifnents made by Dr. M. B. 
Arnold at the Monsall Fever Hospital, Manchester, 
where 300 flies were captured alive and marked with a 
spot of white enamel on the back of the thorax. They 
