48 



cause of their volurninousness $ nor is it necessary to do so in the pres- 

 ent connection. The prime object to be attained is a complete knowledge 

 of the movements of each species. Such knowledge can be gained only 

 by the accumulation of the facts noted by many observers over a term 

 of years. The facts so accumulated will serve as a guide to the time of 

 the appearance and disappearance of each species, and also will serve 

 as a check to the observers' records. By this means the observers will 

 be enabled to correct many mistakes into which they will fall, and will 

 be guided to record many interesting facts which otherwise would 

 escape notice. 



The above points have been dwelt upon in order that no observer may 

 feel slighted should he not find credit given for all his observations. 

 For example, some 60 or 70 stations scattered over every State in the 

 district report the White -bellied Nuthatch as a resident. It is enough 

 for present purposes to say that the species is resident throughout the 

 Mississippi Yalley. Or if, in the records of migration, 5 or 6 stations 

 situated on the same parallel record the arrival of a species about the 

 same time, it is more intelligible to say that on that date the van 

 reached this latitude, than to give the name, latitude, and date for each 

 of the stations.* 



The rule here followed is that the shorter the record the more easily it 

 is comprehended, and the supposition is that the student of this report 

 will always have a map before him. It is useless to attempt to study 

 migration without this aid. 



The remaining or systematic portion of the report aims to be entirely 

 historical rather than philosophical or theoretical ; and it must be re- 

 membered that it is based upon notes, many of which, through lack of 

 sufficient ornithological knowledge on the part of the observer, undoubt- 

 edly are erroneous, but which, since they bear on their face the appear- 

 ance of truth, have been accepted as facts. Hence, while great care has 

 been taken to make the statements as accurate as possible, errors un- 

 doubtedly have crept in, and the author will consider it a special favor 

 if those who discover such will communicate the fact to him. 



There remains the pleasant duty of acknowledging the assistance 

 received from various sources. The first acknowledgments are due to 

 the observers, without whose able and united efforts nothing could have 

 been accomplished. These persons have given their time and thought 

 to the work without compensation, stimulated only by their love of 

 nature and their interest in scientific work; and many have expressed 

 the pleasure it afforded them by the statement " the enjoyment we have 

 derived from the work has more than repaid us. v To Dr. C. HartMer- 

 riam the thanks of all are due for his untiring zeal in bringing the work 

 before the public and enlisting the services of observers, and for the 



[*I cannot agree with Professor Cooke in this method of treating records of mi- 

 gration. Owing to the difference in altitude of stations on the same parallel, and to 

 the influence of topography and other local conditions, I deem it necessary to give in 

 full the exact records of each observer. — C. H. M.] 



