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PREFACE TO THE FOURTH EDITION. 



IN presenting a new edition of the Key to those who are interested in North 

 American Birds, the publishers desire the author to add a word by way 

 of preface. But little need be said of a book which speaks for itself in passing 

 through several editions to supply that demand for a standard textbook of 

 ornithology which this work has itself done much to create, by stimulating and 

 satisfying an interest in one of the most delightful departments of Natural 

 History. 



The part which the Key has taken in the evolution of the subject since 

 1872 is sketched in the " Historical Preface " (pp. xxvi-xxx), first introduced 

 in the Second Edition, 1884. Since the founding of the American Ornitholo- 

 gists' Union in 1883 the impetus then given to the study of birds has resulted 

 in a momentum directly proportionate to the number of workers in this field 

 and to the length of time these have been engaged. I could wish the fruits 

 of such unparalleled activitj'' were all sound and ripe, but they are not ; growth 

 has been forced to some extent in rival hot-houses, and the familiar parable of 

 wheat and tares finds a fresh illustration. Too quick transition from an old to 

 a new order of things in the technicalities of our subject has brought disorder, 

 as usual. Till the pace slackens somewhat, so that we can see where we stand, 

 I do not think it would be wise to recast the Key. 



Therefore, the only change in the present edition is the addition of a Second 

 Appendix, beginning page 897. 



E. C. 



