THE COMMON COCKROACH 



121 



FIG. 34. A, Elytron ; B, Wing 

 of Male Cockroach. 



or tegmina (Fig. 34), are rather stiff and horny, and 

 being dark coloured, do not easily show the very 

 peculiar course of the so-called 

 nervures ; but the under pair, 

 called specifically wings, are ' 

 membranous and transparent, 

 and the nervures can be easily 

 seen. In repose the wings 

 are folded in half lengthwise, 

 the inner half being bent 

 under the outer, and then 

 itself folded like a fan, and 

 they are then covered by the 

 elytra much as in a beetle, 

 though in that case the fold- 

 ing would be transverse instead of longitudinal, and 

 the elytra would not, as they do here, overlap. When 

 closed, the elytra cover the greater part of the back. 

 The females simply have a rudimentary pair of elytra 

 and no wings at all, and flight is impossible to them. 



A cockroach issues from the egg, not, like many 

 insects, with a form totally unlike that of its parents, 

 but shaped very similarly to the adult, and differing 

 from that chiefly in its minute size, its pale colour, and 

 the absence of wings. These young cockroaches may 

 often be seen in kitchen hearths in great numbers 

 little, pale, whitey- brown creatures, running about with 

 extreme agility, and moving their legs so quickly that 

 they seem to skim along or glide over the ground. As 

 they grow, like other insects they cast their skins 

 periodically, after each moult becoming larger and 

 darker. During the first year of its life the young 

 cockroach changes its skin three times the first imme- 

 diately after hatching, the second a month later, and 



