^84 DR. fl. F. IIANCE ON THE 



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sionally lighted. In spite of all this, howeverj the temperature 

 of a Chinese dwelling in the mountain-silk district is during the 

 greater part of the winter considerably below the freezing-point. 

 The worm, being indigenous, could doubtless stand the cold of 

 the winter's night in its cocoon on the bushes on which it forms 

 these latter ; but, apart from theft, destruction by wild animals, 

 insects, &c., it is probable tliat in nights of unusual severity only 

 the strongest and best enclosed might escape perishing from cold. 

 "The natural heat of spring suffices to bring the chrysalis out 

 of the cocoon in the butterfly shape. The butterflies then couple, 

 and in about four or five days after impregnation the female lays 

 eggs. They are laid on native paper spread on mats, tables, &c. 

 In about five or six days, from each of these eggs is produced a 

 small worm of about the size of a black ant, and which is black 

 in colour. This is about the time when the buds on the oak 

 bushes have begun to make their appearance. This must be in 

 the last half of April. The young leaves are forced, by twigs 

 being cut off* from the bushes and placed in water — in pools of 

 the mountain-streams, or in tubs in houses. From these the 

 young tender leaves are taken, and are scattered over the paper, 

 as the worms appear from the eggs. The worms are thus 

 nourished for some days, when they are transferred to the 

 youngest, most tender-leaved oak bushes on the hill-slopes. 

 They are then about an inch in length, but are still black in 

 colour. The transfer of the whole does not take place in one or 

 two days. There is during the whole existence of the animal in 

 its worm stage a difference of eight or ten days in the backward- 

 ness or forwardness of individuals. After some days the worm 

 has its first sleep or torpor, at the close of which it changes its 

 skin, and reappears green in colour and larger in size. It has, in 

 all, four of these sleeps or torpors, each of which lasts about two 

 days. It changes its skin, and becomes larger after each torpor, 

 but retains after the first the same bright green colour. For its 

 next, or fifth sleep, it prepares by spinning itself into a cocoon, in 

 which it assumes the chrysalis shape, then bursts out as a butter- 

 fly and lays eggs, from which the small black worms are pro- 

 duced, when the processes just described are gone through again. 

 These processes are, in the spring season, more rapidly performed 

 than the similar processes in the autumn. The silk-growers 

 told me that those of spring required about GO days, those 

 of autumn about 100. In each season, as fast as the worms 

 consume the leaves on one bush, they are removed by the 



