The fine, soft thread produced by various species of caterpillars in forming the cocoons within which the worm is inclosed during the pupa state, especially that produced by the larv\'91 of Bombyx mori .
(The fine, soft thread; produced; by various species of caterpillars in forming the cocoons) (the worm; is inclosed; T:during the pupa state; L:the cocoons)
The fine, soft thread the worm
produced is inclosed
by various species of caterpillars in forming the cocoons
T:during the pupa state L:the cocoons