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.
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
Countries Producing Raw Silk
Silk raising, or sericulture, has been a leading industry in Japan and China for a great many years, while the Near East and such countries as France and Italy have also played a part in the industry—but to a lesser degree. A great deal of this work, particularly in Japan and China, has been carried on as a home industry, but with the growth of modern business methods more and more of the silk raising has come into the hands of companies operating on a highly scientific basis.
Cocoonery
Japanese Supervision
After many years of experience and experimentation the breeding and care of the silk worm has been put on a very technical and closely regulated schedule that minimizes the chances of loss by waste or the spread of disease. In Japan the industry has been encouraged and fostered by the Government; a special division of the administration is devoted to its attention, and numerous organizations and associations conduct experimental stations for research and study. In fact since about the middle of the 19th century everything possible has been done to foster this highly profitable branch of the country’s industry.