( 363 ) 



MISCELLANIES. 



I.— ON THE KAVAGES OF INSECTS. 



VORACITY OF CATERPILLARS, GRUBS, AND MAGGOTS. 



Insects, in the early stage of their existence, may be com- 

 pared to an Indian hunter, who issues from his hut, as they 

 do from the egg, with a keen appetite. As soon as he is 

 successful in finding game, he gorges himself till he can eat 

 no more, and then, laying him down to sleep, only bestirs 

 himself again to go through a similar process of gorging 

 and sleeping; just so the larvae of insects doze away a day 

 or more w^hen casting their skins, and then make up for 

 their long fast by eating with scarcely a pause. Professor 

 Bradley calculates (though upon data somewhat question- 

 able) that a i^air of sparrows carry to their young about 

 three thousand caterpillars in a week;* but this is nothing 

 when compared with the voracity of caterpillars. Of the 

 latter we have more accurate calculations than that of 

 Bradley, who multiplied the number of caterpillars which 

 he observed taken in one hour by the hours of sunlight in 

 a week. Redi ascertained by experiment that the maggot 

 of the common blow-fly (^Musca carnaria) becomes from 140 

 to 200 times heavier within twenty-four hours ;t and the 

 cultivators of silk- worms know the exact quantities of 

 leaves which their broods devour. " The result," says 

 Count Dandolo, " of the most exact calculations is, that the 



* Account of the Works of Nature. 

 t Esperienze de Insetti, p. 23. 



