SPINNERS AND WEAVERS 11 



beautiful green shaded with blue, and from each of 

 the rings or segments of its body there stand out 

 five stout fleshy spines of red, blue, and yellow, 

 some of them knobbed, and the knobs supporting 

 sharp black bristles. 



There are several other large moths, both in 

 America and India, that produce large silk cocoons 

 of varying texture. In that of the Cecropia Moth 

 the outer portion is so closely woven and the 

 interstices filled in with liquid silk that it is as 

 tough and firm as vellum ; the inner cocoon is of 

 similar consistence, though thinner. An Indian 

 species is described as having the cocoon of leather- 

 like consistence, and Colonel Sykes says it is cut 

 into strips by the Mahrattas and used as thongs 

 j; to bind the barrel and stock of their guns together. 

 Some of the insects that have to make their way 

 through such resisting cocoons when they reach 

 maturity are helped by the chrysalis having a sharp 

 spine in front of the head, with which the more 

 solid envelope may be pierced. In others the 

 emerging moth discharges an alkaline fluid which 

 dissolves the silk at the top of the cocoon and 

 allows the insect to break through. 



Our native Puss Moth (Dicranura vinula) resorts 



f to this method of getting free from the strong box 



\ in which the remarkable caterpillar immured itself. 



To make this cocoon the Puss caterpillar gnaws a 



depression or enlarges a crevice in the bark of a 



tree, and builds over itself a skeleton dome of silken 



net. All over the surface of this net it attaches the 



