IDENTIFICATION OF HOUSE-FLIES 15 



or early in April, whilst the common house-fly is not 

 usually observable until a later date, although it is 

 credited with more generally braving the dangers of 

 attempting to hibernate in the imago stage. My 

 attempts to test the capability of the house-fly by aid- 

 ing October and November flies to hibernate invariably 

 terminated in the creature's death long before spring- 

 time. However, it is very apparent that under the 

 shelter and encouragement of warm winter environ- 

 ments in towns, amidst restaurants, bakeries, large 

 hotels and certain factories, as well as and even more 

 than in mews, adult flies of the latest autumn broods 

 can, to some extent, survive mid- winter with very little 

 or no prolonged hibernation. 



