184 GOAT-MOTH. 



hinder edge of the abdominal segments, which, when 

 one side of the rings is moved forward by the wrig- 

 gling of the abdomen, prevent their sliding back, 

 and the opposite side is brought forward by a repe- 

 tition of the same manoeuvre. The caterpillar dif- 

 fuses a subtile and very peculiar odour, which is 

 felt at a considerable distance, and from its sup- 

 posed resemblance to that of a goat, has caused the 

 insect to be so named. " The object and seat of 

 this odour," says Mr. Knapp, " seem not well un- 

 derstood. Some have conjectured it to proceed 

 from a fluid evacuated from the mouth, and dis- 

 charged to soften the wood in which they burrow. 

 But it seems inconsistent with any probability, that 

 this creature, which is furnished with such very 

 powerful mandibles, should be gifted with an auxi- 

 liary aid to accomplish its object; while, of the 

 many insects that perforate timber, most of them 

 with inferior means, no other possesses an equiva- 

 lent agent to facilitate its labours ; for not one of 

 them, as far as we know, is so supplied. Besides, 

 if such were the purpose, the discharge would be 

 made only when required, and thus this unpleasant 

 odour not always be perceptible. The microscope, 

 too, does not manifest the exudation of any fluid*." 

 This caterpillar attaches itself chiefly to oaks, 

 ashes, willows, and poplars. It abounds in many 

 parts of England, but the moth does not occur in 

 any thing like proportionate numbers. Although 

 the appearance of the caterpillar is disgusting to 

 * Journal of a Naturalist, 295. 



