Cocoons of Silkworms, Japan

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tiff scanned file from original glass slide
The third stage in the life of the silkworm is that of the chrysalis (krs´ å ls) or cocoon period. When the worms have become fully grown they refuse to eat. They are restless, and look about for a corner in which to spin their cocoons. Straw or light brush is put over the trays. The worm begins its weaving. On each side of its head are two openings. Out of these a sticky fluid is thrown in two hair-like fibers. The worm moves its head back and forth so that both fibers are joined. The first of these tiny threads are linked to the straw or brush. Then the worm begins weaving the cocoon about himself. The first threads hold the cocoon in place. While the spinning is going on the room housing the silkworms must be kept very quiet. If any unusual noise or smell is in the place the worms quit work. An overseer can tell at once when the spinning stops. While working, the worms make a soft sound like purring. Tens of thousands of them in a room make a noise like smoothly running machinery a long distance away. In a few days the cocoons are spun. The cocoons are left for about a week before they are gathered up. A few are chosen to be hatched into moths. These moths will lay the eggs for the silkworms of the next year. Most of them are heated to destroy all life. The silk in then reeled off the cocoons. The threads of many damp cocoons are wound together in a single strand. The thread of one large cocoon is from a fourth to a third of a mile in length. The size of the thread depends on the number of cocoons used. Sometimes the threads of 5 or 6 cocoons are wound together, sometimes 15 or 20. These new threads are folded in skeins which are sold as raw silk. Keystone ID: 14750 Note: All titles, descriptions, and location coordinates are from the original Keystone Slide documentation as supplied by the Keystone View Company. No text has been edited or changed.
Copyright by the Keystone View Company. The original slides are housed in McConnell Library's Special Collections.