1G2 



ZOOLOGY. 



of the cotton-tree into threads, and with these sews together 

 the leaves so as to form a nest. 



Even some fishes construct a kind of coarse nest, in which 

 they deposit their ova ; but it is amongst insects that the 

 constructive power is the most remarkable ; and to this we 

 shall return in describing the nests of bees and wasps, and 

 we shall therefore conclude this brief sketch by a single 

 example taken from the class of solitary insects. 



The Xylocope violacea, an insect common enough in France, 

 is allied to the family of bees. This animal (Fig. 105) 

 hollows out in the timber of the hedge-rows, of fruit-trees, 

 and of vine-poles, oval holes, which at first advance obliquely, 

 then curve downwards, and descend vertically for a foot or 

 more : in thus tunnelling the wood, the xylocope takes care 

 to preserve and collect together the debris, with which it 

 afterwards constructs partitions, thus forming cells for 

 lodging the larvae and their food ; in each cell is deposited 

 an egg, and a quantity of vegetable fodder as food for the 

 young so soon as it may be hatched. 



Fig. lOr.-Xest of the Goldfinch. 



329. By instinct, animals lead a solitary life or live in 

 groups; and these groups unite for mutual defence, Each 



