These cocoons are the source of silk fibers, which are made from the cocoons of caterpillars called silkworms.
(These cocoons; are; the source of silk fibers) (silk fibers; are made; from the cocoons of caterpillars) (caterpillars; called; silkworms) (These cocoons; are the source of; silk fibers)
These cocoons silk fibers caterpillars These cocoons
are are made called are the source of
the source of silk fibers
from the cocoons of caterpillars
silkworms
silk fibers