178 THE BOOK OF NATURE STUDY 



movable upon the meso thorax. In the adult the mesothorax 

 carries a pair of short wing-covers (tegmina), and the metathorax 

 a pair of elaborately folded and very delicate flight-wings, whose 

 extremities when folded project for a little distance behind the 

 wing-covers. The legs are set wide apart, and consist of the 

 parts usual in insects, but the tarsus is composed of three joints 

 only. The wings are very remarkable and characteristic. The 

 front pair function merely as covers for the hind ; they are small 

 and hard and of the same brown colour as the rest of the body. 

 The hind pair when expanded are of considerable size and very 

 thin, but when at rest are folded in a most complicated and 

 beautiful fashion, and tucked away beneath the fore-wings with 

 the exception of the small projecting portion. This piece alone 

 is darkly coloured, and relatively firm. The concealment of the 

 hind-wings is so complete that many people are unaware of their 

 presence. It is, however, possible, with some care and patience, 

 to unfold the wings and spread them out with the aid of the 

 blunt end of a needle. The common earwig is rarely seen on the 

 wing, for it hides by day and flies only at night. A smaller species 

 (Labia minor) is commonly met with flying over flower beds at 

 dusk, it being earlier in its habits. The attachment of the wings 

 is peculiar, for the hard part of each is continued towards the 

 mid-dorsal line until it meets its fellow. The folding is more 

 elaborate than is found in any other insect. It is accomplished 

 as follows. The lower radiating veins first come together, creasing 

 the delicate membrane between them fanwise ; a cross fold then 

 is made rather near the basal hard part, and is followed by a second 

 cross fold in the reverse direction close to a line of dilated spots 

 on the divergent veins ; a contraction then occurs close to the 

 base, so that the whole folded structure is compressed, the softer 

 parts passing below the hard ; and finally, the abdomen is turned 

 up and the nippers at its end employed to push all snugly " home." 

 The abdomen is composed of the usual ten segments, and 

 terminates in a pair of horny pincers. The segments are most 

 easily determined in a specimen distended by drowning in water. 

 The separate dorsal and ventral plates which in life overlap each 

 other then become plain, and the seven pairs of minute spiracles 

 in the intersegmental membranes visible on the sides, whereas in 



