OF THE UNITED STATES 319 



ria) are not considered, as they do not properly belong within the 

 lines drawn. They have, to be sure, been placed there in the A. 

 O. U. Check List, but I expect that that was done because the 

 compilers of that volume knew of no other taxonomic position 

 for them. As the male, and female in nearly all warblers, or at 

 least in a great many of them, have a different pattern: ad color- 

 ation of plumage, this, in a collection of them, makes the forms 

 appear to be even still more abundant; while, in the autumn, 

 the plumages of the grown young are often likewise different and 

 apparently increase the number of kinds yet still more. Close 

 study, extending over many seasons can alone familiarize the 

 student with these problems, and render him capable of selecting 

 and naming (technically and in English) the various species and 

 subspecies in such a collection, designating at the same time the 

 females and grown young in their various plumage phases. Very 

 few American ornithologists indeed can, offhand, perform this 

 feat to-day, and if the young plumages are entered in the list, it 

 is safe to say that there is no one living that can do it. These 

 warblers may be classified in about a dozen genera, the vast ma- 

 jority of them falling in the genus Dendroica, it containing nearly 

 thirty specific and subspecific forms; while about a dozen occur 

 in the genus HelminthophUa, and nine or ten in Geothlypis, and so 

 on, some genera being represented by only one, or sometimes 

 two or three, birds. Warblers are denizens of the forests and 

 woods, and are rarely found beyond their confines. Hardly one 

 of them can be said to warble, as their notes, often low and mo- 

 notonous, in no way partake of any such character of vocal 

 music. Some of their notes are very sweet, however, and as a 

 whole they materially add to the great avian choir of sylvan per- 

 formers during the flood of the vernal migrations, at a time when 

 the entire bird-host is in full song. Most of these birds are tree- 

 lovers; others delight in the more humble undergrowth; while a 

 few spend the greater part of their time in bramble or brake, or 

 even upon the ground. All are partial to a great variety of the 

 smaller insects and their Iarva3; and of such food they are almost 

 constantly in search. Indeed, were it not for the check caused 

 by our warblers, many insects would soon swarm to an alarming 

 extent, and plant life would suffer accordingly. A great many 

 kinds of nests are built by these birds, as a rule most of them 

 being tree- or shrub-builders, and exhibit wonderful taste and 

 delicacy in the structures. Great ingenuity is also shown in the 



