oper season for incubation. They are then kept warm during
the time occupied in hatching, sometimes about the person of the
raiser. After a time these eggs hatch out worms, tiny things hardly
larger than the head of a pin. After the worms are hatched they
require constant care and feeding with chopped mulberry leaves till
they reach maturity. They are then about three inches in length, and
spin their cocoons from a fiber and gum which they secrete. When the
cocoons are spun the worms become chrysalises inside of them. The
cocoons are then collected and the chrysalises killed, generally by
heat, before they can again become moths.

=Raw Silk.= The cocoons are next sent to the reelers or filatures. A
number of cocoons, greater or less, according to the size of thread
desired, are placed in a basin of hot water, which softens the gum.
After the outside fibers are removed so that the ends run free, the
ends are collected through a guide and are wound upon a reel. As the
silk cools and dries, the gum hardens, sticking the fibers from the
different cocoons together in one smooth thread varying in size
according to the number of cocoons used. After the silk has been
reeled and dried it is twisted into hanks and sent to America and
other countries as raw silk.

Most of the raw silk of commerce is produced in China, Japan, and
Italy. It is also produced to a large extent in Italy, Turkey, and
Greece, also France and Portugal. The cultivation of silk is not only
carried on by private firms, but is encouraged by the government to
the extent of granting money to the manufacturers.

Various attempts have been made to raise silkworms in the United
States. All have failed on account of the high price of labor
necessary to feed the worms.

=Throwing.= The manufacture in the United States begins with raw silk.
We import our raw silk chiefly from Italy, China, and Japan. It is
handled here first by the "throwster," who winds it from the skein and
makes various kinds of thread for different purposes.

Raw silk wound on spools in a single thread, and called singles is
often used to make warps (that is, the threads running lengthwise of a
piece of cloth) for piece-dyed goods, or cloth which is woven with the
gum in the silk, and afterward boiled out and dyed. Singles are also
sometimes used for filling (that is, cross threads) in very thin
fabrics.

Silk yarn that is used for weaving is divided into two kinds, "tram"
and "organzine.