ORTHOPTERA. 105 



the females in this species have not yet lost the wings, 

 though they have apparently taken the first step in 

 that direction, having ceased to use them habitually, 

 preferring to run and leap when in danger. 



Some Croton bugs are occasionally light-colored : 

 these have just moulted, and their new, soft skin has 

 not yet had time to harden and darken into its natural 

 shade. 



The ancient cockroaches had, and the wild ones now 

 existing have similar forms to those which occupy our 

 houses, and it is evident that their curious adaptations 

 of structure were acquired when living under stones 

 and in narrow shelters before man came into being. 

 Their habits of life and feeding, and the shape of their 

 bodies having fitted them for a hfe of semi- domestica- 

 tion, they, like mice and rats, have naturally been led 

 by the search for food into habitations of all kinds 

 and thriven there on account of the remarkable fitness 

 of their organization. We do not as yet know to 

 what extent, if any, their structures have been modi- 

 fied by the habit of living in houses, and very inter- 

 esting researches might be made upon such points by 

 persons residing in the country, where the wild forms 

 could be studied and compared with those found in 

 houses. 



PHASMID^. 



The walking-stick, Diapheromera femorata, Say, 

 (PI. IV., Fig. 57) is rightly named, since the insect re- 

 sembles a long, slender stick. It imitates nature by 

 changing from a green color in the spring to gray and 

 brown in the autumn, making itself more secure against 



