426 COLEOPTERA. 



result of a combustion kept up by the air of these vessels. 

 This combustion explains the remission of this phosphores- 

 cence observed with the brilliant fire-flies, and which coin- 

 cides, not with the movements of the heart, but with those of 

 inspiration and expiration." (Siebold.) 



The tracheae of the Coleoptera are always highly developed. 

 In the larva state they arise from two principal trunks. In the 

 adult, however, they branch out directly near each stigma and 

 distribute branches which communicate with other main trunks. 

 In those species which fly most, both the fine and larger 

 tracheae end in vesicles, which are distributed in great abun- 

 dance all over the body- In the Luc an idee they are especi- 

 ally numerous, thus lightening the bulk of the enormously 

 developed head. 



The ovaries are arranged in the form of branches of few or 

 numerous tri- or multilocular tubes ; the receptacufym seminis 

 is wedge-shaped and often arcuate, communicating with the 

 copulatory pouch by a long flexuous spiral seminal duct, and 

 there is a liursa cop/ilu-trix usually present. The testes vary in 

 consisting of two long cceca, or two round or oblong folli- 

 cles, or pyriform and placed like a bunch of grapes on the 

 extremity of the vasa defvrtntni, or as in the Lamellicorns, 

 Cerambycidce , Gurculionidcv and Crioceridoe, they are 

 round, flattened, disc-like, and are situated, two to twelve in 

 number, on each side of the body. The organ of intromission 

 is very extensible, composed of the terminal segments of the 

 body, which form a broad flattened, haiiy canaliculated piece. 



The larvae when active and not permanently enclosed (like 

 the Curculio) in the substances that form their food, are elon- 

 gated, flattened, wormlike, myriapodous-looking, with a large 

 head, well developed mouth-parts, and with three pairs of tho- 

 racic feet, either horny, or fleshy and retractile, while there is 

 often a single terminal prop-leg on the terminal segment of the 

 body and a lateral horny spine. The larvae of the Ceram- 

 bycidie are white, soft and more or less cylindrical, while 

 those of the Curculionidoe are footless or nearly so, and 

 resemble those of the Gall-flies, both hymenopterous and dip- 

 terous. 



The pupae have free limbs, and are either enclosed in cocoons 



