32 STUDIES IN INSECT LIFE, ETC. 



nearly every edible thing seems to be covered 

 with flies. 



The proboscis of a fly can only suck up liquid 

 food ; and when we see it feeding on solid sub- 

 stances, such as sugar, it has really dissolved 

 the sugar by depositing some saliva on it, and 

 is sucking up the sugary solution so produced. 

 It not infrequently regurgitates its food in a 

 spherical drop, which it generally reabsorbs. 



As we have seen, flies are very susceptible to 

 temperature, and with the approach of cold 

 weather they seem to die. We used to think 

 that some, in a state of suspended animation, 

 " carried on " through the winter months. This 

 is, however, " non-proven." Many of them un- 

 doubtedly die in the autumn, as bees die, of 

 old age. They are literally worn out. But a 

 great number fall victims to a parasitic fungus 

 called Empusa. Flies killed by this fungus are 

 frequently to be seen in autumn, hanging dead 

 on windows, etc., surrounded by a little whitish, 

 powdery ring of spores formed by the fungus. 



Flies, like many other common insects, are 

 extremely difficult to keep alive in captivity, 

 and few have succeeded in rearing them for 

 more than a month or two. At one time, as 



