66 TRUE TALES OF THE INSECTS. 



wings and the wing-covers rudimental, like tiny sprouts. 

 The body is spinous, furnished with membranous lobes 

 or dilations at the side ; it is spined on the thorax, the 

 abdomen is spined, so are the dilations of the legs, 

 and the peculiar small pyramidal head is strongly 

 spinous at the apex. 



End gained by this Mimicry. 



This armature, these details of form and colouring, 

 may in all cases be regarded as developed for protective 

 purposes. Protection in resemblance, and thus con- 

 cealment, is a very general and very effectual means of 

 maintaining life in the ceaseless struggle for existence. 

 Walking-sticks being perfectly inoffensive and herbi- 

 vorous, and therefore needing no special qualification 

 for facilitating capture of prey, their mimicry is purely 

 defensive, its ultimate end to elude their enemies. 

 Obviously, their harmlessness, their solitary instinct, 

 their sluggish motions, as a rule, and incapacity for 

 what can be properly called flight, their soft and 

 succulent nature, so that they are eagerly devoured, 

 render them particularly open to attack. Their defence, 

 their very existence, depends upon their being by form 

 and colour concealed from enemies. That their vege- 

 table disguises deceive their natural enemies the numbers 



