Silk GENERAL The General Explanatory Note to Section XI should be taken into account in reading the Explanatory Notes to this Chapter. P For the urposes of this Cha ter the term " silk covers not only the fibrous matter secreted by the Bom%yx mori mulberry eeding silk-worm), but also the products of the secretion of similar insects e.g., Bom yx textor known as wild silk. Among the wild varieties, so named because the pro ucmg worm has on y very rarely been domesticated, the most important is tussah silk obta~nedfiom a silk-wonn that feeds on oak. Spider silk and marine or byssus silk (the filaments by which certain shellfish of the Pinna family cling to rocks) are also classified in this Chapter. Generally speaking, this at its vmous stages of silk-worm gut. " ter covers silk, including mixed textile materials classified as silk, from the raw material to the woven fabric. It also includes