VORACITY OF CATERPILLARS, 197 



Sorted leaves. Refuse, 



lbs, oz. lbs. oz. 



First age 6 1 8 



Second age 18 3 



Third age 60 9 



Foi.rtli age 180 27 



Fifth age 1098 102 



Per ounce of esfgs of sorted leaves. ... Ihs. 1362 142 8 

 Refuse \ 142 8 



Lost from the leaves by evaporation, &c. . . 105 



1609 8 

 He adds to this curious table, that from the 1362 lbs. 

 of sorted leaves given to the caterpillars, it is neces- 

 sary to deduct 155 lbs. 7 oz. 4 drs. of litter, consist- 

 ing of fragments of uneaten leaves, stalks, fruit, &c., 

 and consequently that they actually devour only 1206 

 lbs. 4 oz. 4 drs. It is necessary also to mention that 

 of this quantity 745 lbs. 8 oz. of dung are carried from 

 the hurdles ; and consequently there is only digested 

 771 lbs. 7 oz. 4 drs. of pure leaves, which produce 

 120 lbs. of silk cocoons, — giving a loss by evaporation 

 from the worms in gas and vapour of 496 lbs. 4 oz., 

 nearly three parts of this loss occurring in the six last 

 days of the fifth age*. These deductions, however, 

 do not affect the amount eaten by the caterpillars 

 produced from 1 oz. of eggs, which is upwards of 

 1200 lbs. A single silk- worm, as we before men- 

 tioned, consumes within thirty days about 60,000 

 times its primitive weight. 



When we take these facts into consideration, we 

 need not be surprised at the extensive ravages com- 

 mitted by other caterpillars, many of which are much 

 larger than the silk-worm, and all of them produced 

 in broods of considerable numbers. Mr. Stephens, 

 in his valuable catalogue of British insects, a work of 



* Count Dandolo's Art of rearing Silk-Worms^ p. 322—24, 

 Kng. Trans!. 



