Viil INTRODUCTION. 



Natural History Series, and was devoted to a description of the Land Birds occur- 

 ring west of the Eocky Mountains and north of Mexico, liaving been selected 

 as the volume most suitable to succeed those of Geology and Palajontology 

 already published, partly because it was thought that the subject would prove 

 popularly attractive, and partly because circumstances favored its lieing more 

 rapidly completed than the other volumes of the Natural History Series possibly 

 could be. 



For the volume of Land Birds published in 1870 by the California Survey, 

 the biographical portion was chiefly drawn from the notes of Dr. J. G. Cooper, 

 Zoologist of the Survey ; and by mutual consent these notes were placed in the 

 hands of Professor Baird, at that time in charge of the Natural History Depart- 

 ment of the Smithsonian Institution, in order that they might be worked up 

 at the place where a more copious supply of materials and greater facilities for 

 such an undertaking existed than at any other scientific centre in this country. 



The result was the publication, m 1870, of a volume entitled : " Ornithol- 

 ogy. Volume I. The Land Birds." It was illustrated by nearly eight hundred 

 woodcuts, each species (except in the case of the Raptures) being represented 

 by a head of life size, introduced with the text, and intended to be colored by 

 hand, and each genus by a full-length figure, together with numerous diagrams 

 giving the detaUs of wings, claws, and such other parts as are of special value 

 in generic determination. 



During the preparation of this ornithological volume of the California series 

 of Reports, it was agreed between the State Geologist and Professor Baird that 

 the illustrations of that volume should be used by him in a work of larger scope, 

 includmg the Land Birds of all North America ; and this plan was carried out, 

 the result being the well-known work, m three volumes, entitled "A History of 

 North Anaerican Birds : Land Birds," by Messrs. Baird, Brewer, and Eidgway. 

 This work — completed in 1875 — followed closely the California volume in its 

 general style, appearance, and manner of illustration ; the principal exception to 

 this being that the heads were placed together at the end of each volume, and 

 printed by the chromolithographic process, instead of being colored hy hand. For 

 these volumes between seven and eight hundred illustrations were furnished by 

 the California Survey without charge — Professor Baird having promised, in return 

 for this favor, that the portion of the Ornithology remaining to be completed 

 and published as a part of the California Eeport should include all the Water 

 Birds of the continent north of Mexico. The propriety of this stipulation must 

 be evident to all, since it was clear that, after the appearance of the work of 

 Messrs. Baird, Brewer, and Eidgway, there would be only the most limited 

 demand for the much less comprehensive one previously issued by the California 

 Survey. 



