220 THE IDYL OF THE SPLIT-BAMBOO 



jars tipped over sometimes and the water ran down 

 into the " inwards " of the instrument, but it was 

 only the piano that suffered the worms thrived. 

 When, then, you find the soft, fluid excrement in 

 the cage you may know that one or more of the cater- 

 pillars soon will begin to spin. The worm shortens 

 somewhat, as the body-cavity contains little except 

 the empty digestive system and the sacs with the 

 fluid silk. These are two, long, transparent tube- 

 like organs, each about eighteen inches long, of 

 about the diameter of a steel knitting-needle, and 

 curiously coiled and involved in the cavity of the 



ll.R SAC SPI 



Section of Asiatic silkworm (enlarged) showing silk-sac an3 spinnerets 



body. At their front ends they connect with small 

 tubes or spinnerets through which the caterpillar 

 forces the fluid silk in shaping the material with 

 which it spins. The spinning process is a most in- 

 teresting one. When it is imminent the caterpillar 

 crawls restlessly around, seeking a suitable place, and 

 a short film of silk may be seen hanging down from 

 its mouth. If you want to keep some cocoons over 

 Winter for the next season, put the prospective spin- 



