178 ALLEN'S NATURALIST'S LIBRARY, 



woven together with very slender twigs and a little moss and 

 inner hark, the feathers being most numerous in the lining. 



Eggs From five to six and occasionally seven in number. 

 They are quite unmistakable, being of a lilac-grey or stone- 

 grey ground-colour, with spots of black or blackish-brown, 

 varying in size and intensity, but pretty equally distributed 

 over the surface of the eggs, and accompanied by underlying 

 spots of violet-grey, more or less distinctly indicated. Axis, 

 Q'95-1'05 inch ; diam., o 65-075. 



THE WARBLERS. FAMILY SYLVIID^E. 



This is one of the largest families of birds in the Old World, 

 and embraces within its limits an assemblage of widely differ- 

 ing forms. Thus it is extremely difficult to lay down charac- 

 ters by which a student of ornithology may recognise a 

 Sylviine bird, when he sees one alive or has a specimen in his 

 hand. The form of bill is no certain indication, for the form 

 of this organ varies greatly in the Warblers, as it does in the 

 Thrushes. In most instances the bill is rather long, furnished 

 with a small notch before the end of the upper mandible, and 

 having rictal bristles at the gape. In many Warblers, how- 

 ever, the rictal bristles and the notch in the bill are obsolete, 

 while the latter organ is in many forms so flattened that 

 the birds might well be taken for Flycatchers. Warblers can, 

 however, be distinguished from Thrushes by the scuteilation 

 of the tarsus, the members of the latter family always having 

 a plain surface to the tarsus both before and behind, while 

 in the Warblers there are indications of scales on the front 

 aspect of the tarsal envelope. 



There is, however, one great and fundamental difference 

 between the Sylviidce and the Turdidce, first insisted upon by 

 Mr. Seebohm in the fifth volume of the " Catalogue of Birds," 

 and that difference consists in the nature of the plumage of 

 the young birds. Warblers never have spotted young, the 

 latter resembling the adults in plumage, or at least differing 

 very slightly from the latter. Accompanying this peculiarity 

 of the immature plumage, there ensues a corresponding differ- 

 ence in the method of moulting in the two families. Thus a 

 young Warbler, during the first autumn of its life, goes 



