Mr. Bowles has been as good as his word in the matter of coöperation, and has lavished his time in the quest of new species, or in the discovery of new nests, or in the location of choice subjects for the camera, solely that the book might profit thereby. In several expeditions he has accompanied me. On this account, therefore, the text in its pronouns, “I,” “we,” or “he,” bears witness to a sort of sliding scale of intimacy, which, unless explained, might be puzzling to the casual reader. I am especially indebted to Mr. Bowles for extended material upon the nesting of the birds; and my only regret is that the varying requirements of the task so often compelled me to condense his excellent sketches into the meager sentences which appear under the head “Nesting.” Not infrequently, however, I have thrown a few adjectives into Mr. Bowles’s paragraphs and incorporated them without distinguishing comment, in expectation that our joint indebtedness will hardly excite the curiosity of any disengaged “higher critic” of ornithology. Let me, then, express my very deep gratitude to Mr. Bowles for his generosity and my sincere appreciation of his abilities so imperfectly exhibited, I fear, in the following pages, where I have necessarily usurped the opportunity. It is matter of regret to the author that the size of these volumes, now considerably in excess of that originally contemplated, has precluded the possibility of an extended physical and climatic survey of Washington. The striking dissimilarity of conditions which obtain as between the eastern side of the State and the western are familiar to its citizens and may be easily inferred by others from a perusal of the following pages. Our State is excelled by none in its diversity of climatic and physiographic features. The ornithologist, therefore, may indulge his proclivities in half a dozen different bird-worlds without once leaving our borders. Especially might the taxonomist, the subspecies-hunter, revel in the minute shades of difference in plumage which characterize the representatives of the same species as they appear in different sections of our State. We have not gone into these matters very carefully, because our interests are rather those of avian psychology, and of the domestic and social relations of the birds,—in short, the _life_ interests.