REARING SILKWORMS. 59 



seen more plainly as a long narrow duct filled 

 with food in process of digestion. 



If the worm is ready to spin, this duct will be 

 empty, and appear the same color as the other 

 parts of the body of the worm. 



The youngest of the three worms dissected in 

 the same way will show a less proportion of silk 

 in the ducts and a greater proportion of food in 

 the body. There will be found adhering to the 

 inside of the skin a seemingly fatty substance, 

 according to the breed of worm and the quantity 

 and quality of food administered. This will be 

 more or less in quantity. In this substance of 

 the worm the fine ramifications of the silk-ducts 

 lie imbedded. 



After the worms have become hardened in the 

 formalin, they may be opened, and then it will 

 be seen that all the organs have become almost 

 ossified. The ducts will be very brittle, but they 

 may be put in separate bottles for observation. 

 Also, the ducts of those dissected before harden- 

 ing may be kept and shown to better advantage. 



