246 ROMANCE OF THE INSECT WORLD CHAP. 



liability to glide from between one's fingers. Spines 

 and tubercular prominences are likewise present on 

 many caterpillars, rendering them uncomfortable, and 

 maybe painful morsels to assailants. Hairs or spines, 

 however, defend certain species by contributing 

 towards the production of striking protective resem- 

 blance. 



The sting possessed by the females of many 

 Hymenoptera is a defensive attribute that keeps man 

 himself at bay. Obviously it must enable these 

 insects to enjoy considerable immunity from attack. 



Hardness of substance of external parts is probably 

 also protective. The elytra of beetles are often so 

 impenetrable as to be most difficult to pin, and the 

 golden wasps (Chrysididce) which do not sting, have 

 as a substitute the power of rolling themselves up 

 into a ball, which is almost as firm and polished as 

 though it were made of metal. Insects thus endowed 

 must form exceedingly unpleasant and indigestible 

 fare, and will be disregarded by insect-eating animals 

 unless sore pressed by want of food. 



In remarkable vitality insects have another means 

 of defence. Their capacity for increase in other cases 

 is so great that, notwithstanding the destruction of 

 the adults to any number, ample provision seems 

 always to exist for the continuance of the race. 

 Again, some attitudes are protective, such as the 

 simulation of death, or a terrifying posture may be 

 assumed, so as to inspire alarm and repel the enemy. 



Insects defended by some of these kinds of protec- 

 tion in a high degree are free, so to speak, to develop 

 Colour, for sexual purposes probably, and for the 



