Vernon Gilbert Jr., age 12, of Kalispell, Mont., for his question:
DOES SILK REALLY COME FROM WORMS?
Silk is a thread or cloth that is made from the fine web of a certain type of wormlike caterpillar that is called the silkworm. The world s best silk is taken from the mulberry tree eating caterpillar of a grayish white moth called Bombyx mori.
China, Japan and India are leading countries where the silkworms are raised for silk. They are also raised in parts of Asia Minor, France, Spain, Italy and Brazil.
Some efforts have been made to raise silkworms commercially in the United States and England, but so far these attempts haven't been successful. To make silkworm raising profitable, very inexpensive labor is necessary.
Raising silkworms is an art. When the tiny worms hatch, they are placed in trays filled with mulberry leaves. They eat constantly day and night and grow to be over three inches in length. They eat many more times their own weight in leaves.
After 20 to 30 days the worms atop growing. During this time they have shed their skins four times.
When the worms are ready to spin their cocoons, they stop eating and move their heads slowly back and forth. They are put into trays of straw, to which they attach their cocoons. Fine silk threads are spun from spinnerets on the worm's head.
The cocoon is formed around the worm as it swings its head in a figure eight pattern. The spinning of the cocoon takes about three days.
When threads are taken from the cocoon it is called reeling the silk. Cocoons used for reeling are not allowed to mature. The cocoons are exposed to heat and steam to kill the chrysalis within_each one.
Cocoons are placed in troughs of warm water. As much as 500 to 1,200 yards of silk may be reeled from a single cocoon.
Silk reeling houses are called filatures. The twin filaments from five or six cocoons are brought together through a small ring or guide and over the reel. The reeling, which at one time was done carefully by hand, now is done by automatic machines.
The reeled silk fibers are twisted into skeins and then made into "books" of about 30 skeins each. Thirty of these books are packed into a bale. A bale weighs about 130 pounds.
The silk is graded for evenness, cleanliness sad size when it reaches the factory. The skeins are soaked in soap and oil to loosen the natural gum and to make the threads softer.
The softened skeins are then wound on bobbins. Thread is taken from two or more bobbins and wound together on another spool in a procedure called doubling. Additional processing is necessary before the threads can be woven into fine silk cloth.