A. ZIEGLER ON THE CULTURE OF THE SILK-WORM. 381 



by putting the females upon the crates about one foot distant from 

 cacn other, and the males coupled to them. The most experi- 

 enced breeders consider six hours sufficient for the act of pairing 

 to produce good eggs. Some advise to separate them by force ; 

 but this ought not to be done except in case more females than 

 males should have crept out, or if the act lasts longer than from 

 morning till evening. If it be necessary, they must be separated 

 with great care by taking hold of their wings. In case they sep- 

 arate by themselves before the proper time, they must immediate- 

 ly be reunited. If there are more males than wanted, they must 

 be kept in a perforated box, to be used on the following day. 



The female, soon after impregnation, will begin to lay eggs. 

 For this purpose, a frame with cotton or woolen stuff tightly 

 stretched over it has to be placed in a slanting direction against 

 the wall, and the female placed upon it. Slowly crawling upward 

 on this, she will have finished depositing the eggs in 2-i to 48 

 hours. Now she is to be taken off, because the eggs which come 

 later are generally of no account. Those laid within the first 2-i 

 hours are the best. The butterflies close their life soon after hav- 

 ing fulfilled their earthly destination. The breeding-room itself 

 must be kept somewhat dark during their pairing and laying. 



The freshly-laid eggs are of a yellow color, but from ^ay to day 

 they grow darker, until, after about three weeks, they appear ash- 

 gray. In order to loosen them from their places, on a warm win- 

 ter day moisten the cotton in a vessel filled with fresh water, and 

 rub the eggs softly with the fingers. They sink to the bottom, 

 and are dried in the sun after pouring off the water. 



The persons who breed silk- worms must keep themselves very 

 cleanly, and never attend them without previously washing their 

 hands. Sick persons, especially those who have fevers, must 

 never do it ; they must not even enter the breeding-room. Such 

 as incline to perspire freely must neither gather leaves nor feed 

 the caterpillars. Smoking is not allowed in the breeding-room, 

 and in using a snufi'-box great care is to be taken that no tobacco- 

 dust may fall upon the worms or their places. 



Taking off and Assorting the Cocoons. 



The cocoons must not be taken off" before the ninth day. Their 

 perfection is indicated by a rattling of the chrysalis when shaken. 

 The assorting has to be performed at the same time, and the se- 

 lection of the breed-cocoons. This occupation requires great care, 

 because the value and quality of the eggs depend on it. The 

 whole crop may be divided into five classes : 



1. Breed Cocoons. — Those of the strongest texture, surrounded 

 by a rich quantity of flock silk, of a regular shape, must be pick- 

 ed out, and especially those that were among the first spinners, 

 and show a white color. Their being taken off and freed of the 

 flock silk has to be performed with the utmost care. They are 



