146 A COURSE ON ZOOLOGY. 



ducing eggs which undergo the same series of metamor- 

 phoses. 



The fecundity of insects is enormous ; fortunately, the 

 female of the ordinary beetle lays only thirty or forty 

 eggs, which she deposits in a hole made by herself in the 

 ground, and which she covers with earth. From these 

 eggs come the larvae, which become perfect insects only 

 after three or four years, and which during this time 

 make great ravages on the roots and subterranean parts 

 of vegetables. In winter the larvae bury themselves 

 deep in the ground, and pass the cold season in a sort 

 of lethargic sleep. In the spring they come up towards 

 the surface, and if their moment of metamorphosis is 

 come, they appear as beetles in early summer. 



During the heat of day the perfect beetles hide un- 

 der leaves, on which they feed, cutting out as they eat 

 curious and capricious figures ; in the evening they begin 

 to move about with a noisy, ill-directed flight. In some 

 years certain varieties of beetles appear in enormous 

 numbers, and devastate the fields of the farmers, leaving 

 them absolutely bare of verdure. 



CHAPTER XVI. 

 The Spider. 



THE spider belongs to the class Arachnida, which, like 

 insects and crustaceans, forms part of the division Ar- 

 ticulates. 



The body of the spider is composed of but two parts, 

 the head and thorax together forming but a single joint, 

 called the cephalo-thorax. This joint carries on its dorsal 



