MEANS OF DEFENCE OF INSECTS. 219 



efforts of the insect in the employment of those instincts 

 and instruments with which Providence has furnished 

 it for this purpose. 



I. The \)r\nc\pa] passive means of defence with which 

 insects are provided, are derived from their colour and 

 form, by which they either deceive, dazzle, alarm, or 

 annoy their enemies ; or from their substance, involun- 

 tary secretions, vitality, and numbers. They often de- 

 ceive them by imitating various substances. Sometimes 

 they so exactly resemble the soil which they inhabit, 

 that it must be a practised eye which can distinguish 

 them from it. Thus one of our scarcest British wee- 

 vils (Curculio nebulosus, L.), by its gray colour spotted 

 with black, so closely imitates the soil consisting of 

 white sand mixed with black earth, on which I have 

 always found it ; that its chance of escape, even though 

 it be hunted for by the lyncean eye of an entomologist, 

 is not small. Another insect of the same tribe {Bra- 

 chj/rkinus scabriculus, F.), of which I have observed se- 

 veral species of common dors (Ilarpalus, Latr.) make 

 great havoc, abounds in pits of a loamy soil of the 

 same colour precisely with itself; a circumstance that 

 doubtless occasions many to escape from their pitiless 

 foes. — Several other weevils, for instance Brac/i^rhi- 

 nus niveits and eretaceiis, F., resemble chalk, and per- 

 haps inhabit a chalky or white soil. 



Many insects also are like pebbles and stones, both 

 rough and polished, and of various colours ; but since 

 this resemblance sometimes results from their attitudes, 

 I shall enlarge upon it under my second head : whether, 

 however, it be merely passive, or combined with action, 



