lie against the belief in the great sensibility of insects. 

 The very existence of an organ of touch that sense 

 which, in man, is the appropriate organ of general 

 sensibility, and co-extensive with his body itself, being 

 here highly ambiguous is a fact very unfavourable to the 

 opinion that insects were created with great susceptibility 

 to pain. Their integuments are scarcely ever impression- 

 able by simple contact, and as to those who, by placing 

 touch in the antennce only, restrict it almost to a point, 

 they can hardly be said to allow to insects the possession 

 of this sense, nor, of course, of general sensibility at all. 

 At any rate, where the surface adapted for receiving exter- 

 nal impressions from contact, is so exceedingly limited, in 

 the same proportion, one would think, must that sensibi- 

 lity, (of which external impression is the first condition, 

 though by no means all that is necessary to secure the full 

 result,) also decline, or become very questionable, when 

 we speak of creatures whose bodies are nearly covered 

 with horn, whose breastplate is a sort of cuirass, and 

 whose legs are encased in greaves. These, it must be con- 

 fessed, are unpromising conditions for superficial feeling ; 

 but it may be urged that when we run a pin into an insect, 

 we invade a deeper part of the organization ; and that if 

 upon such an injury, the legs seem to be violently agitated, 

 the conclusion that pain has produced that agitation, is most 

 natural, and indeed little short of certainty. But it has 

 been already objected that motions of this kind, like those 

 of a heart recently taken from the body, of which the 

 pulsations can so easily be renewed, only require that pro- 

 perty of the living solid known to physiologists by the 

 name of irritability. Or, if it be said that though some 

 insects are hard and horny in their integuments, others are 

 the reverse ; that caterpillars, for instance, exhibit such 

 violent and convulsive movements when touched, as to 

 make it exceedingly probable that sensation was painfully 

 excited ; that the sense of touch in the spider is known 



