454 
THE STUDY OF INSECTS . 
In this family the third segment of the antenna is ringed 
(Figs. 537, 538) and is never furnished with a distinct style 
or bristle. The wing-veins (Fig. 539) 
are evenly distributed over the wing, 
as the branches of vein III are not 
crowded together as in the follow¬ 
ing family; the costal vein extends 
completely around the wing; the 
alulets are large. 
The flight of these flies is very 
powerful; they are able to outstrip 
the swiftest horse. The males feed 
on the nectar of flowers and on 
Fig. 538. 
Antenna of sweet sap. The mouth-parts of the 
Chry sofis. 1 _ r 
female are fitted for piercing the 
skin and sucking the blood of men and quadrupeds; the 
Fig. 537 
Antenna of 
Tabanus. 
n nii 
females, however, also feed on the sweets of plants when 
they cannot obtain blood. 
The larvae are carnivorous ; many live in the earth ; others 
live in water. They feed on various small animals; some 
upon snails, others upon the larvae of insects. In most cases 
they have a single pair of spiracles, which is situated at the 
hind end of the body; some have a pair of spiracles at 
each end of the body. The pupa is not enclosed in the 
skin of the larva. 
