356 



CHARACTERS OF INVERTEBRATE ANIMALS 



domestica), the piercing parts are much reduced and the mouth 

 is purely suctorial. 



Diptera undergo a complete metamorphosis. From the egg 

 a limbless larva (maggot) is hatched, which becomes a pupa, 



Fig. 207. Structure of Flies (Diptera}, enlarged to various scales 



i, Parts of body: i, head; 0,0, eyes;/, f, antennae; II and in, thorax; c, c, wings; e, e, balancers ; d,d,d,\egs; 

 iv, abdomen, with segments indicated. 2, Head (front view): a, antennae; b, b, eyes; c, forehead; d, d, upper 

 lip; e, e, palps; f, body of proboscis; g,g, suctorial flaps of proboscis. 3, 4, Head (side view); a, antennas; 



b, eyes; d, lower part of face; e, palp; f, proboscis; g t suctorial flaps of proboscis; h, crown of head. 5, Pro- 

 boscis (front view); a, a, palps; b,b, suctorial flaps; c, c, stalk. 6, Proboscis (side view): a, palps; b, suctorial 

 flaps; c, stalk; d, mandibles. 7-10, Antennas of various flies. n, Foot: a, a, claws; b, b, adhesive lappets; 



c, bristles. 



that may or may not possess the power of movement, and from 

 which the adult insect or imago is developed. As the adult does 



not grow in size, the various -sized Flies 

 which are often to be seen on windows and 

 elsewhere are different species, and not, as 

 often supposed, different stages in the growth 

 of the same species. 



The Common Gnat (Culex pipiens) (fig. 

 208) is a representative of a very large 

 family in which the females are distinguished 

 by their blood -sucking propensities, while 

 the males are supposed to live upon the 

 juices of plants. The body is slender, 

 the legs long, and the antennae are well- 

 developed, those of the male being beau- 

 tiful plume-like objects. The eggs are laid on the surface of 

 ponds, &c., a considerable number being agglutinated together 



Fig. 208. Common Gnat (Culex 

 ), much enlarged 



