18 SILK GROWER'S GUIDE. 



times intervening are termed ages. In a colder tern 

 perature, the duration of these several periods is pro- 

 longed ; but in a warm climate, the period or season of 

 the first moulting, which terminates the first age, usually 

 occurs on the fourth or fifth day of its existence ; the 

 second on the eighth or ninth day ; the third on the thir- 

 teenth or fourteenth day; and the last on the twenty- 

 second day. At each of these critical periods, the silk- 

 worms remain in a torpid state, eating little or absolute- 

 ly nothing for a day or more. At the end of about ten 

 days more from the last period, or in about thirty-two 

 days from the beginning, the insect, now fully grown, 

 is about three inches and one third in length, transpa- 

 rent, of a yellowish white or pearl color. Having now 

 completed their fifth or last age, they eat no more, but 

 ascend to the leaves or brushwood, which are placed 

 for the purpose, and commence the formation of the 

 cocoons ; and in the construction of these, the insect 

 works busily and incessantly night and day, during four 

 days. The labor finished, the insect in the centre be- 

 comes transformed to the chrysalis state. 



The vital functions of the silk-worm are accelerated by 

 warmth and the time occupied in passing through the va- 

 rious mutations, is hastened, not only by the increased tem- 

 perature, but materially by the degree of attention which 

 is bestowed on the insects. In Madras, according to 

 Dr. Anderson, and where the climate is very warm, the 

 silk-worm passes through all its evolutions in 22 days. 

 Here then is a saving of time as well as labor, but none 

 in regard to food, as it is admitted that the silk-worms 

 consume the same amount of food to produce the same 

 weight of cocoons, be the term of their lives of a longer 

 or shorter duration. 



The cocoon is usually an inch and a third in length, 

 of an oval form ; the color yellow, or straw, or pure 

 white. The outer covering is like finest wool, and is 

 called flos, and is easily detached ; this being removed, 

 the end of a thread is discovered, of extreme fineness. 



