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LETTER XXVI. 

 ON THE HYBERNATION OF INSECTS. 



If insects can boast of enjoying a greater variety of food than 

 many other tribes of animals, this advantage seems at first 

 sight more than connterbalanced in our climates by the tem- 

 porary nature of their supply. The graminivorous quadrupeds, 

 with few exceptions, however scanty their bill of fare, and 

 their carnivorous brethren, as well as the whole race of birds 

 and fishes, can at all seasons satisfy, in greater or less abun- 

 dance, their demand for food. But to the great majority of 

 insects, the earth for nearly one half of the year is a barren 

 desert, affording no appropriate nutriment. As soon as winter 

 has stripped the vegetable world of its foliage, the vast hosts 

 of insects that feed on the leaves of plants must necessarily 

 fast until the return of spring: and even the carnivorous 

 tribes, such as the predaceous beetles, parasitic Hymenoptera, 

 Sphecina, &c, would at that period of the year in vain look 

 for their accustomed prey. 



How is this difficulty provided for ? In what mode has 

 the Universal Parent secured an uninterrupted succession of 

 generations in a class of animals for the most part doomed to 

 a six months' deprivation of the food which they ordinarily 

 devour with such voracity ? By a beautiful series of provi- 

 sions founded on the faculty, common also to some of the 

 larger animals, of passing the winter in a state of torpor — by 

 ordaining that the insect shall live through that period, either 

 in an incomplete state of its existence when its organs of nu- 

 trition are undeveloped, or, if the active epoch of its life has 

 commenced, that it shall seek out appropriate hybernacula, or 

 winter quarters, and in them fall into a profound sleep, during 

 which a supply of food is equally unnecessary. 



In two of the four states of existence common to insects, 

 in which different tribes pass the winter, namely, the egg and 



