42 INSECTS. 



siderably the smaller) are much larger and more fully 

 developed than the fore wings, so much so indeed as to be 

 able to do the double share of work which falls upon 

 them. Then, to ensure the safety of the wing a wing 

 exceeding in size the sheath which should protect it 

 it is furnished with a double set of joints, which enable 

 it to be folded and packed closely beneath the wing- 

 case. The wing folds longitudinally, and at the same 

 time a hinge-like joint in the longitudinal nerves, about 

 one-third from the tip, allows it to be turned inwards 

 and shortened (fig. 1 6). The process of unfolding this 

 may be easily seen by watching a ladybird, cock- 

 Fig. 16. chafer, or other slow- 

 moving beetle. 



Some beetles are with- 

 out the second fold in 

 the wing, the wing being 

 wider, but not longer 

 Wing of large Water-beetle. than the wing-case. 



Other beetles again, such as the well known " Devil's 

 coachhorse," have the wing-case so short as not to cover 

 a third part of the abdomen, yet so perfect is the folding 

 of the underwing that it is in most cases entirely 

 covered by the wing-case. 



For figures of Order I., Coleoptera, see Plates L, II. ,111. 

 Those beetles which have short wing-cases are fol- 

 lowed naturally by the earwigs, which resemble them in 

 this particular, while they are distinguished from them 

 by the pincer-like termination of the body, and more 

 especially by the form, veiniug, and folding of the 

 wings, which also are not entirely covered by the very 

 short wiog-case, the exposed part being protected by a 

 thickening of the membrane. The wing of the earwig is 



