THE STRATIOMYS CHAM A:LEO. 397 
piercing mandibles are not joined together, but are separated. 
Their wings are provided with a greater number of nervures than 
any others of the order. They live chiefly by sucking the blood 
of animals, especially of horses, and even of man; but the males 
are by no means so sanguinary as the females. These pierce the 
skin of their victims with great facility by means of the lancets 
of their proboscis, while the former live partially from the juices 
of flowers. -The breeze flies are met with chiefly in woods and 
pastures, in the middle of summer, and during the heat of the 
day. When flying they make a loud buzzing noise, and that of 
Tabanus bovinus is well known to cattle and horses, for they 
become very restive at the sound. This insect is a large pale- 
brown fly, marked on the back by a series of whitish spots, and 
the larva is a large, dusky yellowish, cylindrical worm, marked 
by transverse black rings. The larva know nothing about the 
love of blood, but live underground, and have no legs, but they 
manage to feed upon vegetable matters. They are metamorphosed 
into immobile nymphs, which may be recognised by their having 
six spines at the end of their bodies. 
The perfect insects, one upon a tree and the other in flight, are 
shown in the engraving on the opposite page, and the protruding 
proboscis, extended wings, and long legs of these must be com- 
pared with the legless condition of the immobile nymph and 
legless larva which are represented underground in order that the 
extent of the metamorphosis should be appreciated.* 
The metamorphoses of S¢ratiomys chameleo are, perhaps, as 
interesting as those of any other of the Dzptera. It is a 
common fly, and, being bloodthirsty, it frequents flowers in order 
to meet with other insects whose juices it can suck. The larva 
lives in stagnant waters, and is a long creature with coriaceous 
integuments, and its head is small, and is furnished with two 
hooks which are really its mandibles. The terminal segments of 
its body are thin, delicate, and are so narrowed that they can 
enter slightly one within the other like the slides of a telescope, 
or can elongate by being projected backwards ; they form a long 
* It would appear that some species of these flies have larvze which live in water and 
in damp places, under stones and pieces of wood. Mr. Walsh found an aquatic larva of 
this genus, which within a short time devoured eleven water snails (Packard). * 
