COLEOPTERA. 165 



the jaws of the chestnut borer (yBalaniniis caryatf-ypes)^ 

 described below, is one of the most curious examples 

 of the unexpected modifications which sometimes 

 appear. As a rule, not only insects but almost, if not 

 all Crustacea, Myriopods, and Arachnids ; that is, most 

 of the Articulata, have jaws formed from modified 

 limbs, and these organs almost invariably, as might be 

 expected with such an origin, move inwards from the 

 sides, or are opposite to each other like the bases of 

 the legs and appendages from which they have sprung. 

 The power of adaptation possessed by animals is, in 

 fact, so great that organs as a rule seem to have be- 

 come adapted to the performance of the most useful 

 functions, whatever these may be, regardless of what 

 their original duties may have been. 



The grubs (Fig. ii8, b') are soft and footless, fleshy 

 tubercles extending down the sides of the body, and 

 performing the function of locomotion when neces- 

 sary. These larvae resemble those of Hymenopterous 

 insects, to be described hereafter. When ready to 

 pupate, they spin silken cocoons. There are many 

 species of weevils, some of which pass their larval hfe 

 in nuts and grain, while others live in fruits like the 

 plum, grape, and peach. One species, Balaninus 

 caryatiypes, bores into chestnuts and lays its eggs. In 

 these weevils the mandibles move vertically, as stated 

 above. The footless grubs are often found in the nuts. 

 When full grown, the larva finds its way out of the nut 

 and passes the pupa state in the ground. 



The position given to the beetles on the extreme 

 left of the table requires explanation. Notwithstand- 



