METAMORPHOSES OF INSECTS. 



191 



The immense gallery of insect life swells into still grander 

 proportions when we reflect that each insect passes through 

 several metamorphoses or stages of development before it 

 assumes its perfect form, exhibiting as it were several distinct 

 beings during the course of its existence. At first it issues from 

 the egg either as a head-and-footless maggot (a\ or provided with 

 a head and six thoracic legs like a true larva (6), or possessing a 

 still larger number of feet like a caterpillar (c). A boundless appe- 

 tite, an insatiable voracity characterise this first juvenile age of 

 insect life. Thus, to mention but one instance, the silk worm, which 

 at its birth weighs but the hundredth part of a grain, devours 

 in thirty days more than an ounce of leaves, sixty thousand 

 times more than its original weight ! According to this mea- 



Maggot of Hornet. 



Larva of Calosoma 

 sycophanta. 



Apple Moth, with the 



Caterpillar and 



ChrysaLi?. 



sure a child, which when born weighs about ten pounds, would 

 consume during the same period no less than 6,000 hundred- 

 weight of food, to the amazement and terror of its parents. No 

 wonder that so vast a supply of aliment produces a rapid growth, 

 and that, during the thirty days of her existence the silkworm 

 larva increases 9,500 times in weight ; no wonder also that she 

 soon feels her dress too narrow, and more than once sheds her 

 skin to provide room for the swelling proportions of her body ! 

 But now a period of inactivity succeeds, and, generally after the 

 fifth shedding of her skin, a great change takes place in the 



