Beetles : their Structure and Habits, 



6i 



horny pair,i or wing-covers, are closed down tightl\- over the folded flight-wings, 

 their edges meet with marvellous accuracy along the middle line of the body, and 

 their outer edges as accurately fit the marginal border of the body. The majority 

 of beetles live in the earth, in the water, in decayed wood, and so forth, where, but 

 for this arrangement of the 

 parts, the lower wings would be 

 liable to considerable damage. 

 As it is, neither soil nor 

 moisture can find entrance. 



There are numerous de- 

 partures from this typical per- 

 fection of fitting of the wing- 

 covers. In the oil-beetles the 

 shape of these is such that it is 

 impossible for their edges ever 

 to meet, and they are too short 

 to cover the body. In the 

 great family of long-bodied 

 rove-beetles,^ though their 

 edges meet, they are so ex- 

 ceedingly short that the wings 

 have to be folded up under 

 them something after the 

 manner of the same organs in 

 earwigs. In the case of the 

 ground-beetles^ the flight- 

 wings are undeveloped, and 

 the wing-covers have their 

 edges united so that they 

 cannot be separated. This is 

 an instance of atrophy due to 

 their life being spent almost 

 entirely underground. 



Beetles exhibit true meta- 

 morphosis, with an entire 

 change of appearance and 

 structure between the larval 

 and the perfect stages. The 

 larvae of beetles are, as a rule, 

 soft, fleslu' grubs, but there is 

 a great amount of difference 



Photo 6yJ 



Calliper Beetle. 



[£. Step. F.L.S. 



1 hr lore-parts of this bcftle arc shown twice the actual size. U will be seen 

 tli.it the head, supporting the front horn, is comparatively small. The second and 

 taller honi is an outgrowth from the fore-body. In spite of the bearded inner edge 

 of this horn and the saw edge of the other, they do not appear to have any use 

 except that of ornament. 



in the character of their external coverings according to the life they lead. Some 

 are legless and inactive, like maggots ; others have six well-developed legs, and are 

 very active ; some of the grubs of water-beetles have in addition external gills. Of 

 the vast majority of beetles, however, it may be said that at present we know nothing 



' I'llvtia. - Staphylinidac. ^ Carabus. 



