INTRODUCTION. 
peas some apology is necessary for the appear- 
ance of a new American Bird-book. 
Mine must be that the only complete work on Colorado 
Birds is that of Cooke, which, though brought up-to-date 
by successive supplements, is now out of print and very 
difficult to obtain. Moreover, Cooke gives no descriptions 
or keys, so that it is not of much use to the tyro who 
wishes to identify the birds which he has observed or 
obtained: 
The present volume is founded on the very complete 
collection of Colorado birds formed during the last 
thirty-five years by Mr. Charles E. Aiken, of Colorado 
Springs. This collection was recently acquired by General 
William J. Palmer, and presented by him to the Museum 
of Colorado College. As was well known to all General 
Palmer’s intimate friends, he was a great lover of Nature, 
and specially of the wild birds of his adopted State, and 
it was in accordance with his often expressed desire 
that I undertook the preparation of this work, and made 
use of the Aiken collection for the purpose. 
Before arrangements could be made for its publication 
his death occurred. 
The complete volume has, therefore, been dedicated to 
him ; and, as a personal memorial, the necessary expenses 
involved in publication have been defrayed by his sister- 
in-law, Mrs. William Lutley Sclater and his brother-in-law, 
Mr. Chase Mellen, of New York. 
A 2 
