INTRODUCTION. V 



of them without any imputation of censure, but with that charity for the mistakes 

 of others which he hopes to have meted to himself when occasion shall arise. 



To Dr. James Trudeau, hardly less than to Mr. Audubon, acknowledgments must 

 be made for valuable co-operation and assistance. Many years since, almost coinci- 

 dent with his earliest investigations, the design was entertained of a joint work 

 illustrative of American Oology. It has only been abandoned in consequence of 

 the continued absence of Dr. Trudeau from the country, the want of knowledge 

 of his present address, and, above all, the fact that no use could be made of the 

 materials jointly collected for the illustrations. To Dr. Trudeau the writer is in- 

 debted for a large number of valuable and rare specimens, and for a much larger 

 number of drawings, which are often referred to in the text, but which cannot be 

 made use of in illustrating the present work. 



During the past fourteen years, no one has evinced a more constant or more 

 active interest in the subject of the writer's investigations, or contributed more valu- 

 able aid, than Professor Spencer F. Baird, of the Smithsonian Institution. The 

 work itself will present, throughout its entire extent, constant evidences of the as- 

 sistance and co-operation which have been received more or less directly from his 

 zealous and successful endeavors to increase the means of its completeness. 



To the venerable John Bachman, D. D., of Charleston, S. C., to John Cassin of 

 Philadelphia, to Dr. A. L. Heermann, now of San Antonio, Texas, to Charles S. 

 Paine of East Bethel, Vt, to Kobert Kennicott of West Northfielcl, Illinois, to 

 Thure Kumlieii of Fort Atkinson, Wisconsin, to Samuel Jillson of Lynn, Mass., 

 to John Wolley, Jr., of Beeston, England, to Henry F. AValter of London, be- 

 sides many others referred to in these pages, the writer is under many and great 

 obligations, without which his undertaking would have been both more onerous 

 and less successful. 



In mentioning those to whom special obligation should be acknowledged for im- 

 portant assistance, the author refers with pleasure to the services of Mr. L. H. Brad- 

 ford, whose ingenious application of photography to the aid of lithography has 

 given valuable results that could have been reached by no other means. The illus- 

 trations which are due to his intelligent skill are probably the most perfect repre- 

 sentations of eggs that have ever yet been achieved. The credit of this is chiefly 

 due to Mr. Bradford, who has thus greatly contributed to the completeness and 

 value of the work by furnishing illustrations of unsurpassed excellence. 



But above all, his acknowledgments are due to the Smithsonian Institution for 

 the aid which it has afforded in the publication and illustration of this work. 

 Without the assistance the author has received from this source, the memoir could 

 not have seen the light, as its cost would have been greater than his own means 

 would authorize, and beyond all probability of remuneration from sales. 



It would be too soon, in the present condition of the science, to seek to deter- 

 mine how far Oology may ultimately be the means of determining ornithological 

 classification. At present, our knowledge upon this subject is greatly restricted. 

 Only in Europe have any illustrated works upon the local Oology been published, 

 and those are chiefly confined to its more northern portions. We have no knowl- 



