112 NATURE’S CRAFTSMEN 
is removed and burned. Cleanliness and right 
temperature are prime features in the silkworm 
business. The worms are very delicate, and sub¬ 
ject to various death-dealing diseases, chief of 
which is known as silkworm rot, due to a fungus 
growth which takes place inside the caterpillar. 
“ For ease in handling, the sheets of silkworms 
are usually placed on trays of screen-wire or 
wicker. Such trays allow for careful ventilation, 
which is another very important point. About a 
square yard of space will do for the little black 
fellows in the beginning. They are so very tiny 
that it would take thirty-four of them in a 
straight line to make an inch. In two days, how¬ 
ever, so rapidly do they grow that double the 
space is required, and, by the time they are ready 
to spin their cocoons, sixty times as much shelf 
room is required. The skin is changed four times 
during the growth of the caterpillar,—a period 
of eight or nine weeks altogether. And during 
all this time the grower is kept on the jump, pro¬ 
viding food, changing the sheets, and keeping the 
room well-ventilated and the temperature around 
sixty-five degrees. One person, of course, cannot 
begin to do all the work that is required. In 
China and Japan it takes the whole family: the 
boys to gather and chop the leaves, the girls to 
prepare the sheets and do the feeding, the father 
to keep the charcoal burning in the little braziers 
