﻿STRUCTURE, ETC., OF COLEOPTERA. 11 



fourth, fifth, sixth, seventh, eighth, ninth, and tenth, 

 and one on each side of the apex of the eleventh, near 

 the anal opening. The pupa is generally soft, and formed 

 underground; often in a cell or case ; but any peculia- 

 rities in the early conditions of species vrill be noticed 

 hereafter, when the families in which they occur are de- 

 scribed. It may be here stated that the best way to 

 rear either the larvpe or pupse of beetles is to endeavour 

 to keep them in as nearly as possible the same condition, 

 etc., as tliat in which tliey are found. They should not 

 be kept in-doors, but exposed to the natural tempera- 

 ture; and are best kept in large porous earthenware 

 vessels, containing damp earth, etc., and covered either 

 with glass or perforated zinc. Larvae, however, are hard 

 to rear, as they live for so long a time, in some cases 

 nearly three years. 



Want of space prevents us from detailing the nume- 

 rous interesting points of the internal anatomical struc- 

 ture in the Coleoptera : it will perhaps be sufficient to say, 

 that their nervous system is composed of a series of ner- 

 vous ganglia, united by two cords of nerve, as in the 

 other Articulata {vide p. 3) ; that their digestive or- 

 gans consist of a gullet, pouch, gizzard, and stomach, 

 formed by different divisions of one tube (of greater or 

 lesser length) which commences at the mouth, and, after 

 forming the stomach, assumes the usual convoluted in- 

 testinal form, ending at an orifice in the last segment; 

 that there is a circulation of a cold, clear fluid, by 

 means of the alternate contraction and dilatation of se- 

 veral reservoirs or " hearts,''^ joined by one canal; and 

 that air is taken into the system through spiracles, or 

 breath-holes, in the sides, which communicate with two 

 tubes running along the bodj^, one on each side, and 



