49 



THE DIFFERENT AGES, MOULTING, ETC. 



There are several varieties of silk worms.* The most 

 common varieties change their skins four different times. 

 These changes are called moultings, and the intervening 

 times the different ages. The time requisite for the 

 several changes depends greatly on the temperature. If 

 the weather is warm, they will generally happen as fol- 

 lows ; the first moulting on the fourth or fifth day after 

 the hatching ; the second begins on the eighth day : the 

 third on the thirteenth and fourteenth days, and the last 

 change on the twenty second. 



The fifth age lasts aboul ten days; at the end of which 

 the worms have reached their ultimate growth, being 

 three inches in length, t and are prepared to spin their 

 cocoons. Thus thirtytwo days intervene between the 

 hatching and the beginning of the cocoon, and I have 

 known the period retarded to sixty days. These changes 

 will only be noticed by accurate observers. 



FEEDING, CLEARING THE LITTER, ETC. 



Too many leaves should not be given to them at once, 

 and the leaves given should be spread very thin, because 

 if put on too thick, a great number of the worms when 



I saw in the Nursery of Gideon B. Smith, Esq. of Baltimore 

 four different varieties. 1 would recommend, as most profitable for 

 rearing, the large white. 



t See figures 2, 3, 4, 5, or the different appearance of the insect 

 in its different stages. 



