A. ZIEGLER ON THE CULTURE OF TUE SILK- WORM. 375 



eels of two ounces), in low pasteboard boxes, into the not icarmed 

 room destined for their breeding. After leaving them so for five 

 or six days, one may begin to heat it, and to increase the temper- 

 ature of the room, by adding 1° each day, to 16° or 20° R. This 

 must now be kept up day and night, but never above 20°, until 

 the development of the caterpillars takes place. Shaking the eggs 

 lightly every day, the light-gray color will disappear more and 

 more, and, after a few days, the lirst young caterpillars will make 

 their appearance. Now the heat in the room is to be increased by 

 two degrees, and, within three days at most, all the other eggs will 

 open to let the insects out. 



As soon as the first ones show themselves, the eggs must be 

 covered by a piece of gauze, and thin twigs of the mulberry-tree 

 strewn over them, to which the young caterpillars will immedi- 

 ately seek to creep. When a sufficient quantity of these is col- 

 lected upon them, they are transferred to the paper-covered crates 

 by the aid of a pair of small pincers, and arranged in such a way, 

 leaving small intervals, that at each succeeding addition a little 

 more space may be allotted. The gauze must fit exactly into the 

 box, and cover lightly all the eggs. Places where the young cat- 

 erpillars lie too thick upon one another have to be covered by 

 tender leaves, and the insects creeping on these transferred to an- 

 other one. 



The caterpillars are carefully assorted according to their age, so 

 that, for instance, those which crept out in the morning are not 

 placed together with such as come out in the evening, or those of 

 to-day not with those of the preceding day. After three or four 

 days the creeping out must cease ; all those that have not come 

 out are not farther to be considered. If the breeding comprises 

 more than one ounce of eggs, it is advisable not to lay them out 

 all at once, but at intervals of several days, thus preventing all 

 the caterpillars from becoming ripe enough to spin at the same 

 time. Each separate parcel may be called a breed. In this way 

 five or six of them may be produced in the same year. 



Tlie Food of the Caterpillars. 



The smaller the quantity of food given to them, but the oftener 

 a day, the more it will benefit them. About seven or eight times 

 within 24 hours would therefore be the best polic}^, and of these, 

 the main meals, in the morning, at 4 to 5 and 10 to 11 o'clock ; in 

 the afternoon, at 4 to 5 ;. and at night, at 10 to 11 ; the interven- 

 ing meals being given after 7 A.M., 2 P.M., and 8 P.M. At 11 

 o'clock P.M. a larger quantity of leaves may be given, and stopped 

 during the balance of the night, while the caterpillars have not 

 yet shed their skin for the last time. When this, however, has 

 been done, they become much more voracious, and must now be 

 fed even during the night. 



In the beginning the caterpillars require only very tender 



