EXCESSIVE NUMBERS OF LARVAE. 131 



eggs ; now, if there were only twenty larvae in a 

 certain locality which lived through the winter, 

 and became perfect insects in May following, the 

 eggs deposited by these would, supposing all to 

 be hatched, produce, according to a calculation 

 made by Reaumur, in the course of a single 

 year, eight hundred thousand larvae. Well may we 

 exclaim, then, with this learned author, " Should 

 we not rather wonder at the wisdom and fore- 

 thought which has ordered matters so that these 

 insects increase to annoy us so rarely?" The 

 wonder is, in truth, not that they should multiply 

 so excessively at particular periods, so much as 

 that it should be so seldom that they are multi- 

 plied even to the extent of which they are natu- 

 rally capable. Thus, if we suppose that all the 

 eggs of the moths of this species were to be 

 hatched, it is more than probable that a large 

 portion of our vegetation would be consumed by 

 them. How is this guarded against ? In various 

 ways. The eggs are not all capable of being 

 hatched, or if so, are not allowed to escape injury 

 by various accidents, and the Iarva3 themselves are 

 a prey to countless enemies among the birds, 

 while they also frequently perish owing to the 



