An encyclopedia entry on the silk-worm, the caterpillar of Bombyx mori. It describes the insect's anatomy, growth and moulting, feeding on mulberry leaves, cocoon spinning, and the length of thread per cocoon. It also covers the Ailantus silk-worm (Bombyx cynthia), introduced into Europe in 1856, its food tree, cocoons and floss silk. Two engravings show the Ailantus moth and the Ailantus silk-worm with cocoons.