4 PREFACE 



(4) They are adapted for the use of beginners in the study 

 of birds, not for reference by ornithologists, who have access 

 to more comprehensive vrorks. 



Keys, if properly arranged, furnish the easiest and most 

 practicable method of enabling beginners to identify species. 

 The Keys in this book were originally prepared as aids in 

 discovering the names of birds by examination of their 

 external features only. They were thus printed, and used 

 by over a thousand students under the direct supervision 

 of the author. Every difiiculty encountered by the pupils 

 suggested to the author changes to render the Keys more 

 effectual; and now, after their final revision, they are so 

 simply and carefully arranged that even a child can follow 

 them with ease, and discover by their aid the names of 

 birds both in the hand and in the bush. 



Two series of Keys have been introduced : 



(1) Keys to be used only with birds in the hand; that is, 

 with prepared skins, mounted specimens, or recently killed 

 birds. These place emphasis on the parts which change 

 least with age, sex, or season, and give exact measurements 

 of these parts. 



(2) Keys to be used in the field for identifying the living 

 birds that frequent our fields and groves. These emphasize 

 such features as can be seen with the naked eye or through 

 an opera glass, with the birds at some distance from the 

 observer. In these Keys the birds are separated for conven- 

 ience into groups, determined by their relation in size to our 

 most familiar birds, the English sparrow and the robin. 



The illustrations were drawn especially for this work by 

 Miss Ada Collins Apgar and Mr. Richard B. Farley, and 

 their scientific accuracy and careful execution add much to 



