21 



I could not detect any epidemic or any well-defined 

 sickness among them, nor did there appear any difference 

 in those reared in the open or in the shade, or on the large 

 or small trees, or under cover ; insects, birds, mice, rats, 

 squirrels, and lizards carried them off repeatedly, but the 

 reason of so much life being lost was that I tried to 

 preserve more than I had food for ; in fact, they died from 

 preventible accidents. 



" One of the most interesting, and I think important, 

 facts that I have this year been able to prove, is with 

 regard to the composition of the cement with which the 

 caterpillar hardens its cocoon. 



"Former analyses of this agent made for me, in England 

 by Dr. Taylor and in Bombay by Dr. Lyon, had shown 

 that it contained the acid urate of ammonia, that it was 

 in fact excrementitious ; and this year, by opening the 

 cocoons at various intervals, I was able to convince myself 

 of the fact that when the caterpillar has left off feeding 

 and begins to spin it voids the food remaining in the 

 alimentary canal, first of all in a more or less solid form 

 and of a dark colour, but after it has become fully en- 

 veloped in the cocoon the excrement comes away as a 

 light-coloured liquid, the hue and consistency of which 

 depend upon the amount of vegetable matter not pre- 

 viously evacuated and the amount of lime, carbon, and 

 ammonia present. The respective proportions of these 

 ingredients vary, I presume, with the food on which the 

 caterpillar has fed and with the state of the atmosphere at 

 the time of spinning, also the longer they remain coating 

 the fibre the harsher and more discoloured it will be. It 

 is therefore very necessary, I think, to remove this cement at 

 a very early date ; and this chemistry has shown the manu- 

 facturers how to do. Judicious feeding, too, may alter its 

 nature. Before long, fresh cocoons will be at an early 

 stage thoroughly cleansed from all discolouring matter, and 

 Tasar silk will be available for manufacturing purposes as 

 colourless as it is when first put forth by the caterpillar. 



" Through the kindness of my correspondent in Santhal 

 country 1 have procured a few cocoons of the large or 

 Chattisgharl variety of the Tasar moth, and as this crosses 

 readily with the small or Desi variety which only is found 

 in the Southern Maratha country, I hope next season to 

 procure larger cocoons than I usually do." * 



* Geoghegan, ;< Silk Industry of India," p. 111. 



