September, 1909.3 



Sericuliurei 



been experimentally grown at Pusa, and 

 it is being grown also at other parts of 

 India, from seed obtained from Pusa. 



Eri silk has peculiarities which distin- 

 guish it from all other silks cultivated or 

 collected in India. In the first place, the 

 worms require only castor leaves for 

 food ; mulberry is not a food-plant. In 

 the second, the cocoon is not a closed one 

 and is not reelable in the same way as 

 are mulberry or tusser silk cocoons. The 

 caterpillar, in preparing the cocoon, 

 leaves one end closed only with converg- 

 ing loops of silk, so that, while nothing 

 can get in, the moth can push out ; but 

 the cocoon is made in layers, is not com- 

 posed of a single thread and cannot be 

 reeled by the ordinary process. On the 

 other hand, the silk has its immense 

 advantage, that the cocoons do not 

 require to be "stifled," i-e., killed, to 

 prevent the egress of the moth ; in pre- 

 paring mulberry and tusser silk, the 

 cocoon is killed, since the moth in getting 

 out so damages the cocoon that it cannot 

 be reeled so well ; in eri silk this is not 

 so ; the moth, as here utilised for spinning, 

 must be allowed to emerge, and the 

 taking of life, so abhorrent to many 

 classes in India, is not necessary. 



Another feature, shared with the 

 " indigenous " mulberry silk-worm, is the 

 number of broods ; seven or eight broods 

 are obtained yearly, and as the produc- 

 tion of eggs is large, a large brood can be 

 secured from a small quantity of initial 

 seed when castor is plentiful, and several 

 crops of cocoons are obtainable yearly. 

 The insect is completely domesticated 

 in the sense that it will not run wild and 

 become a pest ; the whole life is passed 

 in captivity, and the moths do not 

 attempt to leave the rearing house. 

 Rearing can be done in any building ; 

 the Pusa rearing has been done entirely 

 in a grass and bamboo house. Lastly, 

 the silk cocoons can be utilised just as 

 cotton is, but yield a cloth far more 

 durable and lasting ; the cocoons are 

 boiled, and then spun in the ordinary 

 way that cotton is ; the thread produced 

 can be woven just as cotton thread is, 

 and the cloth produced, while not so 

 fine as machine woven cotton cloth, is 

 white, durable and much in demand. 

 Dyed cloth is produced with ease by 

 dyeing the cocoons, the thread or the 

 cloth ; and E. R. Watson has shown that 

 silk is more easily dyed in fast colours 

 with the ordinary indigenous dyes than 

 is cotton, and that the dyeing of silk is 

 easier than is the dyeing of cotton. 

 With the indigenous and the synthetic 

 (aniline) dyes, a great range of colours 

 can be introduced, and the dyeing offers 

 no special difficulties. 



We here discuss eri silk solely from 

 one point of view, its rearing and utili- 

 sation in this country by ordinary indi- 

 genous methods suited to any part of 

 India. The question of building up an 

 industry in this silk for export or for 

 utilisation in India with power machi- 

 nery for turning out the beautiful spun 

 silks of commerce, is not here touched 

 on, nor is the kindered question of 

 producing reeled silk from these cocoons. 

 The work of the past two years has 

 been directed to ascertaining how far 

 this silk can be utilised in India, and it 

 is our belief that silk of this kind can 

 be grown, spun and woven in a very 

 large part of India, almost wherever 

 the castor plant is grown. The eventual 

 fabric thus produced is "Assam" silk, a 

 very durable strong cloth, suited to the 

 requirements of this country ; but it 

 must not be assumed that the finer silks 

 of great delicacy and with beautiful 

 gloss can be obtained. Fabrics more 

 akin to cotton cloths are produced, but 

 with the great durability characteristic 

 of this silk, and by methods familiar in 

 this country and requiring no appliances 

 beyond those in ordinary use. It is im- 

 possible here to give detailed and 

 complete directions for the cultivation 

 of eri silk, but we deal with some of the 

 more important points ; anyone wishing 

 to commence the cultivation can obtain 

 eggs and fuller instruction from Pusa. 



Rearing.-— The insect lives, as otner 

 insects do, iu four stages ; the moth lays 

 eggs, which hatch to worms which feed 

 on the leaf of the castor plant; the 

 worms moult four times, at each moult 

 increasing iu size ; when full grown they 

 retire into hiding and spin the cocoon ; 

 in this they change to the chrysalis, 

 which lies motionless in the cocoon and 

 requires no food ; from this the moth 

 emerges which is of either sex; the 

 sexes pair and the females lay eggs. 

 The insects require attention in only 

 two stages, the worm and the moth. 

 The eggs are placed on a tray and left 

 till they hatch. In dry weather they 

 are covered with a damp cloth. When 

 they are about to hatch, or when the 

 first one is seen to hatch, they are covered 

 with the youngest and smallest leaves 

 of castor, spread out over them. They 

 crawl up on the leaves and feed, and 

 they can be removed attached to the 

 fine leaves and put in a clean tray. As 

 more hatch, the leaves are lifted and 

 transferred. At first they are fed on 

 the young leaves, washed free from 

 dust if necessary, At intervals, moults 

 occur, the worms ceasing to feed and 

 throwing off their skin. This is a time 

 when, if any are weak, they die. There 

 are four moults before the last, the last 



