MEANS OF DEFENCE OP INSECTS. 227 



The powers of annoyance^ by means of tlieir hair, 

 with which the moth of the fir, and the procession-moth, 

 before noticed % are gifted, are doubtless a defensive 

 armour to them. — Madame Merian has figured an 

 enormous caterpiihirof this kind, — which unfortunately 

 she could not trace to the perfect insect, — by the very 

 touch of which her hands, she says, were inflamed, and 

 that the inflammation was succeeded by the most ex- 

 cruciating pain''. The vesicatory beetles, likewise, 

 {Lytta 'cesicaioria, F., &c.) are not improbably de- 

 fended from their assailants by the remarkable quality, 

 so useful to sii fieri ng- mortals, tljat distinguishes them. 



Your own oliservation must have proved to you, that 

 insects often escape great perils, from the crush of the 

 foot, or of superincumbent iveights, by the hardness 

 of the substance that covers great numbers of them. 

 The elytra of many beetles of the genus Jlisicr are so 

 nearly inipenetrable, that it is very difiicult to make a 

 pin pass through them ; and the smaller stag-beetle 

 {Lucamis pnraUeJopipedus^ L.) will bear almost any 

 weight — the head and trunk forming a slight angle with 

 the abdomen — which passes over it upon the ground. 

 Other insects are protected by tlie toughness of their 

 skin. A remarkable instance of this is afforded liy the 

 common forest-fly {Hippohosca equina, L/.), which, as 

 was before observed', can scarcely be kiUed by the ut- 

 most pressure of the finger and thumb. 



The invctluntary secretions of these little beings 

 may also be regarded as means of defence, which either 

 conceal them from their enemies, make them more 



'•" Vol.1. 2d Va\. p. 131. ^ " Insect. Sin-imim. I. 57. 



^' Vol. I. 2d Ed. p. 119. 



Q 2 



