INTRODUCTION. 



With the founding of the American Ornithologists' Union, the Nuttall Ornitholog- 

 ical Club suspended publication of its Bulletin, or rather consented to merge that 

 quarterly in the -'Auk" for the purpose of giving the latter its undivided support. 

 It is not now intended to withdraw, or in any way weaken this support, but as the 

 Auk is already overcrowded and often unable to accept long papers, the Club has 

 decided to begin a series of Memoirs, which will be issued irregularly, as material 

 offers, each to consist of a single paper, or of several papers relating to the same or 

 kindred subjects. 



Of this series, the following article is the first. It was originally presented by Mr. 

 Brewster to the American Ornithologists' Union's Committee on the Migration and 

 Geographical Distribution of North American Birds. The Committee being unable 

 to publish it at once, the Chairman, Dr. Merriam, has kindly oflered it to the Club, 

 with the following letter : 



Washington, D. C, 

 William Brewster, Esq., January 26, 1886. 



President Nuttall Ornithological Club^ 



Cambridge, J\/ass. : 

 Dear Sir : 



In response to your letter of the 21st inst., I beg to say that I have read your 

 paper on Bird Migration with much interest. I regard it as a communication of un- 

 usual importance and thank you for your courtesy in presenting it to the American 

 Ornithologists' Union's Committee on Bird Migration. 



The Committee regrets its present inability to publish the document as soon as its 

 importance demands, and therefore, in accordance with your suggestion, returns it 

 herewith, in the hope that the Nuttall Ornithological Club will issue it at once as a 

 special contribution. 



Very truly yours, 



C. HART MERRIAM, 



Chairman of the Commitlee on the Migration 

 and Geografhical Distribution of North 

 American Birds. 



