VIREONINE TRAITS 489 



learned that all are really 10-primaried. The most obvious 

 distinctioa is that which Bonaparte originally acted on in pro- 

 posing to range under " Vireosylva " such specimens as oKva- 

 ceus} but the arbitrary discrimination between those with an 

 obvious spurious quill, and those in which the Ist primary is 

 rudimentary, separates such intimately related species as gilvus 

 and philadel^hicus, while it unites others as distinct as flavifrons 

 is from olivaceus in most respects. I am led to return all the 

 Vireos under the original head, in view of the fact that almost 

 every single species has its own particular details of form as 

 well as of color. The specific characters in this group are for 

 the most part very constant and tangible, though requiring in 

 many cases nice discrimination, so curiously interrelated are 

 these birds. 



They are an interesting and agreeable tribe of little birds, 

 simply-colored, in harmony with the foliage amidst which they 

 live, and numerous enough, both in species and in individuals, 

 to form a marked feature of our sylvan Ornis. Most of the 

 Greenlets, including all the larger species, as the Eed-eyed, the 

 Blue-headed, the Yellow-throated, and the Warbling Yireos, in- 

 habit high open woods, and the shade- trees of our parks, lawns, 

 and public streets; while the smaller ones, like the White-eye 

 of the East, and Bell's, and the Least Greenlet, live down in 

 the shrubbery with the Chats, Thrashers, and Oat-birds. Be- 

 ing mainly insectivorous, though they also feed on berries, they 

 are migratory in our country, and appear with all the periodicity 

 of the Warblers themselves; different Vireos nestle anywhere 

 in the United States, and some of them are among our most 

 numerous and conspicuous summer visitors ; few go much, if 

 any, beyond the United States, and only exceptionally reach 

 high latitudes. They are very agile and industrious birds, 

 indefatigable in the pursuit of insects, nervous and highly ani- 

 mated in bearing, voluble and versatile in song, each kind 

 having its own musical accomplishments. Though insignificant 

 in size, Greenlets are spirited birds — the plucky little Eed-eye, 

 for instance, will defend itself when wounded with all the cour- 

 age of a Hawk ; and some of the most touching scenes I have 

 ever witnessed among the birds have been those when Green- 

 lets sought to protect, encourage, and sympathize with a 

 stricken mate. The Greenlets all build one style of nests, a 

 rather slight and thin-walled, but neat and compact, pensile, 

 cup-like structure, suspended from the fork of a twig ; and the 



