INSESSORES. 313 



birds all the musical birds, including the Nightingale of the 

 Old World, and the Mocking-bird of the New, belong to the 

 division which we are now to consider. 



The Dentirostres are spread over the globe. They are com- 

 prised in five families, viz: (1.) Silviada, or Warblers; (2.) 

 Merulidce, or Thrushes ; (3.) Muscicapida, or Fly-catchers ; 

 (4.) Ampelidce, or Chatterers ; (5.) Laniadce, or Shrikes. 



FIRST FAMILY. THE WARBLERS. 

 Silviada. (Lat. Sylvia, or Silvia, a wood.) 



The small singing birds comprised under the general name of 

 Warblers, form a very numerous, as well as interesting group. 

 The bill in these birds is slender, straight, awl-shaped, higher 

 than it is wide at the base, and furnished with bristles, the lower 

 mandible being straight. Audubon enumerates no less than 

 forty-four species of these birds found on the American Conti- 

 nent. The habits of the different species vary considerably ; 

 but in general, the Warblers frequent groves and woods, and 

 search for the small insects, which are their food, among the 

 leaves and twigs, and the crevices in the barks of trees, rather 

 than on the wing, like the Swallows. 



Excepting the Humming Birds, we find among this group, the 

 smallest birds of the creation. The diminutive Golden Crests, 

 Regulus ; the Nightingale, Pliilo?nela ; the White-throat, or 

 Petty-chaps, Silvia, or Curruca, (Lat. caterpillar;) the Wood- 

 warbler, or Wood- wren Sylvicola, (Lat. wood inhabitant,) are 

 examples of genuine warblers. 



Diffused over all parts of the habitable world, it seems to be the 

 office of these birds to prevent an undue multiplication of the innu- 

 merable insects which lurk within the buds, the foliage or the flow- 

 ers of plants. The smallness of these insects, causes them to 

 elude the notice of the Thrushes and the larger insectivorous birds, 

 whilst their habits secure them against capture by the Swallows 

 and other birds that take their prey only when on the wing. 



The Warblers are, for the most part, migratory birds. When 

 the increasing warmth of spring is ushering the insect tribe into 

 renewed life and activity, the return of these birds is providen- 

 tially and wisely ordered, to prevent its troublesome increase. 

 In autumn, when the hosts of insects begin to diminish, and no 

 longer require to be kept in check, these useful little creatures 

 take their flight to other climes. 



The Warblers may be conveniently arranged into five groups, 



