THE STRATIOMYS CHAM^LLO. 39/ 



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 hve 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 larvae 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 Stratiomys chamceleo are, perhaps, as 

 interesting as those of any other of the Dipteva. 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 "oriaceous 

 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 larvre 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), 



