カイコ
Silk is a naturally produced fibre obtained from many species of the silk moth. In 1700 the favoured silk was produced by a moth (Bombyx mori), that spun a cocoon to protect the larvae. The larvae fed on mulberry leaves grown in Italy. Silk fibres from the Bombyx mori silkworm have a triangular cross section with rounded corners, 5–10 μm wide. The silk is a protein, fibroin, that was cemented in place by the use of gum, another protein, sericin.