262 LIFE AND HER CHILDREN. 
These "balancers" tell us that the two-winged 
flies, the gnats, mosquitoes, midges, bluebottles, house- 
flies, and cattle-flies, are not made on a different 
plan from the four-winged insects, but are merely 
flies whose hind wings have lost their size and power, 
while the front ones have become stronger and larger. 
This has evidently been no disadvantage in their 
Fig. 89. 
Daddy-long-legs.* 
b, Balancers. 
case, for they have flourished well in the world, and 
myriads are to be found in every town and country, 
while their different ways of living are almost as 
various as there are kinds of fly. Some, such as 
the daddy-long-legs, suck the juices of plants, some 
suck animal blood, some live on decaying matter ; 
while in not a few cases, as among the gadflies, the 
* Tipula. 
