114 
NATURE’S CRAFTSMEN 
black mulberry and lettuce leaves are also used 
sometimes. But nothing gives as good returns 
as the white mulberry. The red mulberry and 
the paper mulberry are said to be quite worthless 
for silkworm feeding. 
“ Each time the caterpillar moults it becomes 
paler in color, the reason being that each succes¬ 
sive coat has fewer black hairs in its nap. When 
full grown, the worm is nearly three inches long 
and quite naked. Its color now is usually a yel¬ 
lowish-gray; wild varieties are much darker. All 
the time the worm has been growing two large 
glands or sacs have been forming along its sides. 
These sacs are the spinnerets. They open into 
the silkworm’s mouth, for like all caterpillars 
these little creatures dribble their thread. For 
five days before the worm is ready to begin spin¬ 
ning its appetite is hard to satisfy. It eats every 
waking moment, until at last its needs are filled, 
when it begins to grow stupid and languid, and 
the grower makes haste to provide a quantity of 
small brush, clumps of rice straw, or arches 
formed of fine wood for the workers to fasten 
their cocoons upon. These are placed in rows 
about sixteen inches apart, so that the caterpillars 
may have ample room. Now, too, the tempera¬ 
ture is raised about ten degrees. 
“ Shortly each spinner has selected a site for 
his silken house, and is busily engaged on the 
