Attempts to establish the industry in America have been generally unsuccessful, high costs precluding the possibility of competing with foreign conditions. In addition, the raising of raw silk has been built up principally in countries where there is a system of home industry—a social and industrial system never developed in the United States. However, although America has never been a factor in the producing of the raw material, it has risen to a place of utmost importance in the manufacture of the finished textile. Immense quantities of raw silk are imported from abroad—principally Japan, Italy, and China—and its conversion into the finished products constitutes a most important part of our industry. 2. THE SILK WORM [Sidenote: _Names and Types of Silk Worms_] The textile fibre known as silk is a filament secreted by one of two general types of moth larvæ—the cultivated and the wild. The largest proportion is, of course, made up of the former, produced by the worm known as the _Bombyx mori_, while the most common type of wild silk worm is called the Tussah. The name _Bombyx mori_ comes from the name of the family to which the silk worm belongs: the _Bombycidoe_ (spinners), and _mori_, from the _morus multicaulis_ or mulberry tree, on the leaves of which it feeds. The species _Sericaria mori_, or silk worm of the mulberry, belongs to the generic class of _Lepidoptera_ or scaly-winged insects. [Sidenote: _Bombyx Mori_] The _Bombyx mori_, with which we are chiefly concerned, is divided into other groups according to the cycle of reproduction. The annuals reproduce once a year, and sixty per cent of the silk worms belong to this class. The bivoltines reproduce twice a year, and the polyvoltines, several times during the year, the first crop being the best. [Illustration: _Full Grown Worms_] The study and development of the various phases through which the silk worm passes, leading up to its production of the actual filament, have been a subject of intense research in many parts of the world for a great number of centuries. The present silk worm is nothing more than a highly specialized product of a long train of artificial cultivation. [Sidenote: _Stages of Growth_] The cultivated silk worm passes through four changes in its life of two months, i.e., egg, larva, chrysalis (or pupa), and adult—a cream-white moth which is about one inch in length. The moths live only a few days, during which mating takes place, and the female lays several hundred eggs; after about six months these eggs hatch into worms. The latter pass through what are known as four “molts,” or shedding of the skin, before the worm matures, spins its cocoon, becomes a chrysalis, and finally emerges as a moth. This, very briefly, is the life history of the silk worm. 3. MODERN SERICULTURE [Sidenote: _Countries Producing Raw Silk_]