THE FLY 



87 



water \vith the eggs of the mosquito, and reach man's Ijocly 

 again if the water be drunk by him. 



The crane-flies (Tipulidae/ Fig. 93) look like mosquitoes, 

 but can easily be distinguished from them by the fact that 

 they have a V-shaped groove on the back of the thorax. They 

 are larger, and have relatively longer legs than the mosquito. 

 Their legs are easily broken, and seem to be so much in the 



Fig. 9.3. —a crane-fly. Nat. .size. Photo, by W. H. C. P. 



way that flight is clumsy. The adults are quite harmless, but 

 some of the larvse work destruction by feeding upon tender 

 plants and causing them to wther and che. 



There remain to be consiflered a number of degenerate flies — 

 degenerate because parasitic in the adult state. The first 

 familv we may consider is that of the louse-flies.^ These 

 small insects have a firm proboscis used for piercing, and stout 

 legs. Only certain of the genera develop wings, and some of 

 these lose them after they gain their hosts. They live, like 

 lice, in the fur of mammals or the feathers of birds. They 



' Latin, tipula, water-spider. ' Suborder Pupipara. 



