PUSS MOTH. 91 



handle so strange-looking a creature. To add to 

 the threatening aspect of the larva, it has the 

 power of ejecting from an aperture under the 

 head a fluid -which may perhaps have the power 

 of keeping off certain foes, but -which has no 

 effect upon the human skin. 



The caterpillar feeds upon the -willow, and 

 -when it is full-fed it crawls down the trunk of 

 the tree and gnaws a slight oval hollow in the 

 bark. With the fragments of the bark and a 

 glutinous secretion which it ejects, it constructs a 

 cocoon of wonderful hardness, so hard, indeed, 

 that a strong knife is required to make any im- 

 pression on it. Being formed of the bark, it is 

 so closely assimilated in colour and general ap- 

 pearance to the trank of the tree that detection 

 is almost impossible. 



On the first occasion that I ever possessed one 

 of these larvae, it was put to great inconvenience. 

 It had been brought to my rooms at college while 

 I was out, and the servant had placed it on the 

 stone mantelpiece and covered it with an inverted 

 tumbler to prevent it from escaping. The larva 

 happened to be full-fed, and was constrained by 

 instinct to prepare its cocoon. It could find no 

 material either in the tumbler or the mantel- 

 piece, so it was forced to content itself with the 



