48 TRUE TALES OF THE INSECTS. 



Defenceless, and incapable for the most part of rapid 

 movement or of flio^ht, the Walking-Sticks have no other 

 means of escape from their enemies than to pass un- 

 detected, in concealing their existence from other animals 

 by their immobility. It is this immobility that renders 

 effective the extraordinary and important characteristic 

 that distinguishes them — their imitative resemblance to 

 vegetative objects. Thanks to it, they succeed in 

 effectually deceiving the eye of the sharpest enemy. 

 Little as it might appear, they have considerably less 

 to fear birds as foes, by which some are much relished 

 for food, than small animals that prowl among the bushes, 

 particularly lizards ; and among insects the Mantidai, 

 which live in the same spots, and are armed for battle 

 in a manner that no Phasma could resist. Several bugs, 

 too, suck the Phasmidai. One species is known to have 

 harboured Ichneumon-flies in its body without suffering 

 any apparent harm from their presence or their emer- 

 gence. There is perhaps no other group of insects 

 which is so generally imitative, and w^hich naturalists 

 have experienced greater difficulty in detecting in their 

 haunts, a difficulty heightened by their habit of living 

 solitary, or in pairs. Apterous individuals, such as 

 Diapheromera, however, seem to possess gregarious 

 tastes, often a whole colony being found clustered to- 

 gether, distributed over the branches of the same bush. 

 Having succeeded in discovering one, the investigator. 



