480 The House Fly. [ August, 
As we have said, when the fly leaves its pupa-case it pushes 
away the front end of the case, which opens like a lid, by means 
of the distention of the membranous front of the head, which 
may be seen pushing out and in as the fly walks rapidly about. 
This bladder-like expansion is evidently distended with air and 
in connection with the air-tubes within the body, so that it may 
serve the temporary purpose of enabling the fly to disengage 
itself from its pupa-case. When free from its prison the fly 
walks or rather runs nervously about, as if laboring under a good 
deal of mental excitement, and quite dazed by the new world of 
light and life about it, for as a maggot it was blind, deaf, and 
dumb. Now its wings are soft, small, baggy, and half their final 
size. The fluid that fills them soon, however, dries up, the skin 
of the fly attains the colors of maturity and it soon flies off with 
a buzz suggestive of contentment and light-heartedness born of its 
mercurial temperament. ‘That the fly not only throws off in its 
buzz songs of the affections, love ditties, but also may vary its 
notes accordingly as it is elevated or depressed in spirits concern- 
ing more trivial and less absorbing matters, we are assured by 
Sir John Lubbock, who says that the sounds of insects do not 
merely serve to bring the sexes together; they are not merely 
“ love songs,” but also serve, like any true language, to express 
the feelings. 
The life of the house fly may, then, be summed up as follows: 
It lives one day in the egg state, from five days to a week as a 
maggot, from five to seven days in the pupa state, —in all, 
from ten to fourteen days in the month of August, — before so 
winged adult period. It is often asked how long-lived a fly 18- 
Most of the flies which are born in August live for a mon ig 
six weeks, and die at the coming of frost, either of cold or pe 
the attacks of fungoid plants. A few probably winter over ane 
survive until midsummer, and thus maintain the. existence 
this useful species, to which civilized man owes more than he can 
readily estimate, and with which he can dispense only when the 
health of. onr cities and towns: is. looked. after wit Si greater 
vigilance and intelligence than is perhaps likely to be the oa 
for several centuries to come. 
a 
