PREFACE 
TO THE SECOND AND THIRD VOLUMES. 
The author’s original intention, as announced in the preface to 
the first volume of this work, was to have devoted the second 
exclusively to water birds, reserving for the third the few unpub¬ 
lished land birds which he at that time possessed. Having since 
however, by extending his researches to the most opposite and 
remote parts of the Union, fortunately succeeded in procuring a 
sufficient number of land birds to make up a volume, or perhaps 
two, by themselves, he has changed his original plan for one 
which is more systematical, and which moreover enables him to 
complete the series of the numerous and interesting order of 
Passeres. All the remaining land birds of the United States will 
then be, the three large Vultures, the most interesting of which, 
the Condor, is already drawn; the Strix cinerea, the largest Owl 
known; and the Californian Quail.* 
* Two of the Vultures are figured by Temminck in the Planches Coloriees; Cathartes 
californianus, PI. 31, and Cathartes gryphus, PI. 133, the male, and PI. 408, the young 
female. The latter species had also been previously figured by Humboldt, Ohs. de Zool. 
The third, Cathartes papa , was long since figured by Buffon, PI. Enl. 428 ; and also by 
Vieillot, Gal. des Ois. PI. 3, under the name of Gypagus papa. 
Strix cinerea has never been represented, and was ranked by us among those species 
which from their not having for a long period come under the observation of naturalists, 
we considered obsolete. We have recently ascertained that it inhabits near Lake 
Superior, and intend that it shall occupy a plate in a future volume, along with several 
Hawks, which though represented by Wilson, we think it necessary to figure in various 
states of plumage in order to clear up the intricacy of their history. 
Perdix californica has been figured by Lapeyrouse, Shaw, and others. 
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