ROACHES AND OTHER ANCIENT INSECTS
ended only when the last of the brood had been devoured. The mother roach was not at the time molested, but next morning she lay dead on her back, her head severed and dragged some distance from the body, which was sucked dry of its juices—mute evidence of the tragedy that had befallen sometime in the night, probably when the pangs of returning hunger stirred the centipede to renewed activity. The house centipede does not confine itself to a diet of live roaches, for it will eat almost any kind of food, but it is never a pest of the household larder.
Fig. 52. The common house centipede, Scutigera forceps (natural size), a destroyer of young roaches
Most species of roaches have two pairs of well-developed wings, which they ordinarily keep folded over the back, for in their usual pursuits the domestic species do not often fly, except occasionally when hard pressed to avoid capture. The front wings are longer and thicker than the hind wings, and are laid over the latter, which are thin and folded fanwise when not in use. In these characters the roaches resemble the grasshoppers and katydids, and their family, the Blattidae, is usually placed with these insects in the order Orthoptera.
The wings of insects are interesting objects to study. When spread out flat, as are those of the roach shown in Figure 53, they are seen to consist of a thin membranous tissue strengthened by many branching ribs, or veins, extending outward from the base. The wings of all insects are constructed on the same general plan and have the
