PREFACE. ix 



Vogel of Max Fiirbringer. To Professor Gadow I am 

 indebted for a great many titles of works which I have 

 incorporated in the bibliography which is found at the 

 end of this volume ; still, I have personally examined 

 the majority of books there enumerated. 



English and American literature, as I have already 

 stated, furnishes us with no good handbook to the 

 subject. 



Frequently, an author, as he closes his prefatory 

 remarks, finds that he has a host of helpful friends to 

 whom his thanks are due for assistance rendered : it 

 proves to be the exception in the present instance, for 

 all of the material used was collected by myself ; all the 

 dissections were made by myself ; all the descriptions 

 are in my own handwriting ; and the drawings were all 

 drawn directly from the dissections by myself. Still it 

 gives me pleasure to remember here my friend Dr. J. L. 

 AVortman, the biologist of the United States Army 

 Medical Museum, who, several years after this volume 

 was written, carefully passed over wnth me the mus- 

 culature of the shoulder-joint in birds, and verified my 

 dissections upon the Eaven, comparing them with 

 similar studies he was at the time engaged upon in the 

 Raptores. Further it gives me pleasure to express my 

 thanks to Dr. G. Brown Goode, of the United States 

 National Museum, for having upon a number of 

 occasions furnished me with the means of preserving 

 my somewhat extensive material, and that, too, when 

 my labours upon the present volume were being 

 prosecuted in New Mexico, between two and three 

 thousand miles from civilization, the libraries, and the 



