HABITS OF THE ADULT FLY 
59 
number of flies by August 20th. Major N. Faichnie, 
referred to above, in experimenting with flies in India 
in the summer, found that they lived eleven days only. 
Mr. Jepson, in his notes on the breeding of the com¬ 
mon house fly during the winter months, incidentally 
mentions the fact that during the summer of the pre¬ 
vious year (1908) in no case was he able to keep flies 
alive for more than three weeks, and then only with a 
few individuals; whereas, as previously stated, flies 
reared during the winter were kept alive for eleven and 
one-half weeks, and flies caught in kitchens in Febru¬ 
ary were kept alive for ten weeks and had presumably 
been living since the previous autumn. 
If we take Jepson’s statement of three weeks as be¬ 
ing the probable limit of the life of the adult fly in 
midsummer, and if we conclude, as we must, that the 
average life at that period is much shorter than this, 
it becomes evident from what will be stated in the fol¬ 
lowing paragraph that after the female fly has laid her 
eggs in summer she has not much longer to live. The 
plain inference from this will naturally be that the hi¬ 
bernating flies in the winter time are probably for the 
most part females which have not laid their eggs. Un¬ 
fortunately for the conclusions just stated. Doctor 
Hewitt records the fact that he has kept flies in cap¬ 
tivity in the summer time for seven weeks, while Grif¬ 
fith (1908) was able to keep a male sixteen weeks. 
Ficker (1903), in an account of experiments carried 
on between June and October, states that he kept flies 
alive in confinement for four weeks, feeding them on 
