INSECTS 



359 



Fig. 210. Scales from Wings of various Butterflies 

 (greatly enlarged) 



these scales gives rises to all sorts and combinations of colours, 

 often of extreme beauty. The male and female of the same 

 species are often very different in appearance. 



The head, which is well-marked off from the thorax, bears 

 long antennae and prominent compound eyes, while its mouth- 

 parts are converted into a 

 \ongproboscis, carried rolled 

 up into a spiral when not in 

 use (fig. 2 1 1 ). This organ 

 is used to suck up the nectar 

 of flowers or, in some cases, 

 liquid matter of a less sa- 

 voury kind, but differs en- 

 tirely in structure from the 

 corresponding organ of a 

 Fly. The upper lip is incon- 

 spicuous, and the mandibles 

 have disappeared altogether, 

 while the second maxilla are fused into a small plate bearing two 

 conspicuous palps. The sucking part is formed entirely from the 

 much -elongated first maxillcz, each of which is a long jointed 

 structure grooved deeply on its inner side, so that when approxi- 

 mated to its fellow a 

 tube is formed, the 

 firmness of which is 

 often enhanced by a 

 series of interlocking 

 hooks. 



The thorax bears 

 not only the wings, 

 but three pairs of 

 weak legs, and is 

 fairly well marked 

 off from the abdomen, which is generally elongated, but may either 

 be very slender or else broad according to the species. 



The life-history of a Moth or Butterfly furnishes a good 

 example of complete metamorphosis. The eggs are laid upon 

 some special food-plant, and the larvae which hatch out from 

 them are ravenous caterpillars which feed upon vegetable matter 

 or, more rarely, other substances. The head is provided with 



Fig. an. Heads and Proboscides of various Butterflies (enlarged) 



