THE GOAT MOTH. 431 



caterpillars, while the remainder of the block was equally well 

 stocked with these larvae. 



One of these caterpillnrs, about one-fourth grown, is shown 

 at Fig. 6, and a curious-looking creature it is. The skin in 

 very smooth and shining, and without hairs, except some stiff 

 bristles which project from each segment. These are not so 

 conspicuous in the larva as in the drawing. The colour is pale 

 mahogany, except the head and a hard plate on the second 

 segment, which are black. The body is rather flattened, the 

 head is wedge-shaped, and furnished with very powerful jaws. 

 When full-grown the caterpillar exceeds three inches in length, 

 and is as thick as a man's finger. The strength of a full-grown 

 larva is enormous, and its powers of forcing its way out of the 

 vessel in which it is confined must be seen to be appreciated. 

 I have kept many of these larvae, and never felt sure of them. 

 They were continually escaping. Putting them into a wooden 

 box was quite useless, as they ate their way through the side in 

 a very short time. Putting them in a tin box was equally 

 useless unless the cover were tied down, for they had a way of 

 pushing at the lid round the edges, and so gradually opening it 

 sufficiently to permit their escape. Even perforated zinc is not 

 safe from them, for I have known my caterpillars to find out a 

 place where the zinc has been cracked, fix their short and 

 powerful jaws in the holes, and fairly twist down a flap through 

 which they managed to force themselves. 



The odoui- which these creatures give out is equally powerful 

 and enduring, and to many persons is peculiarly hateful. 

 Whether from use or not I cannot say, but I do not find it 

 nearly so offensive as the odour of many other insects, such as 

 the Dyticus beetle and the Lace-wing fly. The odour per- 

 meates the whole of the tunnels, and for years after they have 

 been deserted the scent is sufficiently strong to denote the 

 inhabitant. 



When the larva is full-fed it forms a cocoon made of 

 fragments of gnawed wood and silk. The cocoon is very tough, 

 and will withstand much rough handling. These cocoons are 

 oval, similar in shape at both ends, flexible, and yellow in 

 coloiur, and are very strongly scented with the odour of the 

 insect which made them. There is considerable variety in the 

 size of the cocoons, and some are barely half as large as others. 



