INTRODUCTION. 
11 
the reproduction of particular tints. As having the high- 
est reputation and perhaps the greatest merit, the colors 
manufactured by Messrs. Winsor & Newton of London, 
and Fr. Schoenfeld & Co. of Dusseldorf, have been chiefly 
selected as the standards for this work. The colors 
manufactured by these firms embrace so great a variety 
that it has been found possible to identify with them a 
large number of those named in descriptions, the mixture 
of two or more being of course occasionally necessary. 
In regard to the external anatomy or " topography " of 
a bird, a system as little complicated as possible is desir- 
able. The one presented in this work, while substantially 
the same as that usually adopted, and offering no innova- 
tions, is considerably simplified, thereby greatly facilitating 
the acquirement by the student of a knowledge of this 
essential adjunct of descriptive ornithology. 
It is believed also that the figures representing the 
typical forms of color-markings, and of egg-contours, and 
the concordant scale of different standards of measurement, 
will also be found of great practical utility. 
The author has in every case endeavored to give the 
plainest possible definition of a term consistent with 
accuracy. All expressions having reference solely to 
internal characters, and which therefore seldom if ever 
enter into ordinary descriptions of birds, have been ex- 
cluded, though many anatomical and osteological terms 
occasionally employed in diagnoses of the higher groups, 
and others pertaining to the general treatment of the 
subject, are considered and carefully defined. 
Acknowledgments are due from the author to several 
friends for their generous assistance. Dr. Leonhard 
Stejnegee suggested and prepared the comparative scale 
of standard measurements and the tables for the con- 
version of English inches to millimetres, and vice versa, 
