140 MISS MAUDE L. CLEGHOR>f ON THE IXHERITANCE OP 



that in some of the generations the univoltine females do not 

 hatch, and in others the univoltine, males, but in F^ when all the 

 eggs hatched the sex-ratios were also unequal. 



Method of Rearing of Worms. 



To ensure choosing distantly related moths for rearing from, 

 I reared the silkworms of each laying seiDarately, and the cocoons 

 were also kept separate by keeping the silkworms after their fourth 

 moult in rounded trays with a double inner circle of plaited strips of 

 bamboo, about an inch and a half from the outer edge, forming 

 a space into which the silkworms readily crawl to sereposit their 

 cocoons. When the cocoons are removed from the trays, they 

 are placed in rows on large sheets of white paper on which is 

 noted the number of the laying from which they were reared. 



Each cocoon is covered over with a small earthen cup, the- 

 common Indian chilum. A day or two before the moths come out, 

 the cocoon is cut open to remove chrysalis and weighed. 



The weight is noted and the chrysalis put back. When the 

 moths emerge, the pierced cocoons are removed from under the 

 earthen covers and placed within the opening at the top of the 

 covers for reference, and this also to prevent the moths from 

 getting out. By referring to the number of the layings and to the 

 numbers of the two parent cocoons (which is also noted on 

 the paper), the choosing of the distantly related moths for 

 rearing is simplified. 



If I had been rearing on a large scale I should have kept four 

 or six families separate for seven or eight generations, then bred 

 them together, and from these again four or six families would 

 have been separated out. 



In these experiments the silkworms have always been fed most 

 during the night, as I have noticed that, in the wild state, the 

 larvae of moths mostly feed up to 9 or 10 a.m., and then restart 

 feeding at about 5 or 6 p.m. Even young silkworms, which 

 I kept on a small potted mulberry plant under observation, hardly 

 ate at all during the day, though surrounded by fresh leaf on all 

 sides. I find that silkworms always eat most voraciously between 

 10 p.m. and 4 a.m., so it is unnatural for them to be forced to 

 feed all day, which is usually the case by the native rearers, and 

 may well be one of the causes of their degeneracy. 



They should have a rest of at least seven or eight hours during 

 the day, and be fed every three or four hours during the night, 

 stai^ting late in the afternoon at about 6 p.m. If there is an 

 abundant supply of leaf, they might with advantage be fed every 

 two hours. Newly hatched worms should always be fed every 

 two hours between 5 p.m. and 10 a.m. The worms if fed well in 

 the last stage after the fourth moult will give good cocoons, even 

 if not very well fed in the earlier stages, but it is most essential 

 that they be well fed throughout the larval stage for them to be 

 vigorous and healthy. 



