THE SILK-WORM. U5 



of mulberry. As soon as hatched, the worms crawl 

 through the holes of the netting and begin to feed. 

 They are then carried on the net to the table where 

 they are to remain. A busy place is the silk-worm 

 room, after life begins. The worms are fed twice a day. 

 The newly hatched caterpillar is black or gray, and 

 is covered with long, stiff hairs. By and by it grows 

 into a cream color, and its hairs disappear. It eats its 

 own weight of leaves every day. During the few days 

 before beginning to spin, it consumes more than during 

 its whole previous existence. To make room for its 

 rapid increase it changes its skin four times at intervals 

 of from four to ten days. This experience in the silk- 

 worm is called ''sickness." The time from hatching 

 to spinning is about forty days. 



Silk-worm Caterpillar (after Riley). 



When about to spin, the worm ceases to feed and 

 throws out threads. The silk comes from a fluid 

 within, which issues from a spinneret just beneath the 

 lower lip. As the air strikes the fluid it hardens. 

 First the worm throws around itself a loose silk called 

 floss, as a sort of frame- work. Then within this it 

 spins a tough, strong, continuous thread, not in circles, 

 or round and round, but back and forth in loops like 

 a figure 8. A single cocoon may contain a thread 

 four thousand yards long, or about two and a quarter 

 miles long. The work occupies three or four days. 



