蚕怎样吐丝

蚕怎样吐丝
蚕怎样吐丝

蚕怎样吐丝
How do silkworms make silk?
　　Silkworms,offspring of moths,produce their highly-desirable,pricey silk,by spewing out thread from tiny holes in their jaws,which they use to spin into their egg-bearing cocoons.This entire production takes a mere 72 hours,during which time t
　　hey produce between 500-1200 silken threads.These miniature,mulberry leaf-munching marvels lay,at minimum,500 eggs each spring,thereby increasing the number of workers for the production line.
　　The ancient Chinese unearthed the silkworm's secret,and were the first to spin the silkworm's threads into cloth.They kept this covert,top-secret operation,from the rest of the world by imposing the death sentence upon those who smuggled the worm or its eggs out of China.Eventually,however,the secret was out,and silkworms are now farmed for their silk,in China,of course,in Japan,in India,in France,in Spain,and in Italy.These countries harness the power of the silkworm through a tedious,labor-intensive,time-consuming process,a process which prominently figures into the price of silk.
　　Farm workers painstakingly place the 500 plus eggs the grayish-white moth lays,upon strips of paper or cloth,until the following spring,when the incubated eggs hatch,and the tiny,black worms emerge.Once hatched,workers transport the worms to trays brimming with the worm's favorite fodder of finely chopped,white mulberry leaves.After approximately 6 weeks,the satiated worms begin slowly to sway their heads back and forth to signal that show time is at hand.
　　Once the silkworm completes its cocoon,the farmer snatches his cocoon from him,to prevent the shrunken chrysalis,carefully encased inside,from hatching into a moth in 12 days.The silk farmers ensure that this event does not transpire,and does not kill his moneymaking venture,by exposing the cocoons to heat,thereby executing the chrysalis.Now,the silkworm's labor of love is prepared for the silk production process.
　　The process begins by bathing the now-empty cocoons in troughs of warm water,which serves to soften the gum binding the silken filaments together.He now proceeds with the arduous task of unraveling several cocoons,and winding the filaments onto a reel that twists 10-12 filaments together into a "single" thread of silk.The end product is a skein of raw silk,which the farmer profits from by selling to the highest bidder.