THE DEVIL'S RIDING-HORSE (MANT/D/E). 27 



unobserved, without attracting the fatal attention of 

 enemies. Not only this, but in such districts the indi- 

 viduals of the green colour, being most conspicuous, will 



FIG. 9. Chceradodis rhombicollis, with prothoracic expansion and leaf-like elytra. 



be readily devoured ; and generation after generation the 

 grey form will tend to repeat itself, to the gradual exclu- 

 sion of the other ; so also the grey form will disappear 

 in verdant regions, where the green specimens will be 



