The Larva and the Nymph 



singular, as we shall see. As for the re- 

 sistance of the cone-shaped end of the cocoon, 

 we discover that this is due to a plug of 

 crumbly matter, violet-black and sparkling 

 with a number of black particles. This plug 

 is the dried mass of the excrement which the 

 larva ejects, once and for all, inside the 

 cocoon itself. The same stercoral kernel also 

 causes the darker shade of the cone-shaped 

 end of the cocoon. The complicated dwell- 

 ing averages twenty-seven millimetres in 

 length, while its greatest width is nine milli- 

 metres.^ 



Let us return to the violet varnish that lines 

 the inside of the cocoon, I thought at first 

 that I must attribute it to the silk-glands, 

 which, after giving a glossy coat to the double 

 wrapper of silk and the scaffolding, have still 

 a secret store of the fluid. To convince my- 

 self, I opened some larvae which had just 

 finished their work as weavers and had not 

 yet begun to apply their lacquer. At that 

 period, I saw no trace of violet fluid in the 

 silk-glands. This shade is found only in the 

 digestive canal, which bulges with a purple- 

 coloured pulp; we find it also, but later, in 

 the stercoral plug relegated to the lower end 



^1.05 X .35 inch. — Translator's Note. 

 103 



