178 FIELD ZOOLOGY. 



be able to discover that carrion flies — flesh flies — breed 

 in decaying carcasses and also in some other places coming 

 closer to the life and health of the human family. (Fig. 

 72.) Notice what happens in hot weather when meat 

 from the dining table is not disposed of in a cleanly way 

 after the meal. 



It will be easy to catch some half dozen flies in a room, 

 school-room or other room. Try to discover with the 

 hand lens whether the six flies are all of the same sort, 

 that is if they look alike. Bear in mind that, when a 

 fly emerges from its pupal case, it comes out adult in size 

 as well as in powers. Do you find any stable flies among 

 the half dozen captured? 



An expedition should be made to the open fields; 

 and for this the dip net will be better than the butterfly 

 net. You are going after flower flies, and you will find 

 them hidden in flower clusters. Bring your dip net 

 over a flower cluster, give the flower stem two or three 

 decided taps, and you may be rewarded by the upward 

 flying of several glistening green or otherwise brilliantly- 

 colored flies. If you have with the other hand kept the 

 net open, the flies will fly upward into the top, and you 

 can fold the net over upon itself once and keep them 

 prisoners long enough to have a good look at them with 

 your hand lens. These are the syrphids or flower flies; 

 though it is quite possible that you will also find in your 

 net some of your beetle friends which also frequent 

 flowers. The syrphids are the flies that have been 

 occasionally known to eat solid food, a few pollen grains; 

 but all other dipters, so far as known at present, partake 

 only of liquid food, excepting the rasping off of sugar 

 crumbs, but these are soon dissolved in the mouth fluids 

 and are also swallowed as is the usual liquid food. 



