434 



ZOOLOGY. 



perfect animal. The time during which the bombyces re- 

 main thus shut up in a state of chrysalis, varies according to 

 the temperature. If the heat be from 15 to 18 (from 59 

 to 65 Fahrenheit), they come out in the perfect state from 

 the eighteenth to the twentieth day. To pierce their cocoon, 

 they moisten one extremity with a particular liquid which 

 they disgorge, and afterwards they strike their heads violently 

 against the point thus softened. When the bombyx has in 

 this manner finished its metamorphoses, it appears under the 

 form of a butterfly with whitish wings (Fig. 454) ; its mouth 

 is no longer armed with jaws as when young, but is pro- 

 longed into a proboscis rolled into a spiral; its limbs are 

 slender and elongated, and its internal conformation differs 

 as much from that of the larva as its external form. Soon 

 after their birth the papillons seek each other ; afterwards 

 the females lay their eggs, the number of which amounts to 

 more than five hundred for each of these insects; finally, 

 after having lived in the perfect state from ten to twenty 

 days, they die. 



Fig. 454 Bombyx, or Moth of the Mulberry. Fig. 455. Chrysalis 



of this moth. 



533. The bees, of which we have already had occasion 

 to speak ( 332), experience changes still greater, since in 

 the larva state they have no limbs, and resemble little 

 worms. It is the same with flies, gnats, and a great number 

 of other insects ; thus the vermiform animals which swarm 

 in putrid flesh, and which are known by the common name 

 of maggots, are nothing else but the larvaB of the golden fly. 

 Gnats, which at night vault in the air in numerous groups, 



