PREFACE TO FOURTH EDITION. V 



As soon as the new classification was available the chairman 

 drew up a systematic list of all proposed changes in nomenclature 

 and additions and subtractions of species or subspecies that had 

 not been covered by the Supplements, as well as cases brought up 

 for reconsideration, and with this as a basis prepared fourteen 

 "questionnaires" which were typed under the direction of Dr. 

 Wetmore and distributed in sequence to the members for study 

 and vote. It was impracticable to bring the Committee together 

 for frequent meetings and this correspondence method gave the 

 members more time for careful consideration and discussion of the 

 problems presented. Upwards of five hundred cases were pre- 

 sented and voted on in this way. In the few instances where the 

 Committee was so nearly divided that there was either a tie vote 

 or a majority of one, no change was made nor a proposed new 

 form accepted, since it was felt that where such difference of 

 opinion existed the only hope for stability was in adherence to 

 current usage. 



While the questionnaires were being circulated the chairman 

 revised the ranges of the various species and subspecies to the 

 best of his ability, in the light of information published since the 

 appearance of the third edition, and also checked up references 

 and type localities, amplifying both as explained below. In the 

 latter work he is under deep obligations to Dr. Richmond whose 

 vast knowledge of the subject rendered possible the verification 

 of many references otherwise unobtainable. With the votes of 

 the Committee incorporated in the revision thus prepared, the 

 chairman drew up the text of the new Check-List using cut-up 

 copies of the third edition as a basis with all new material typed 

 and properly inserted. This manuscript was then submitted to 

 Drs. Grinnell, Richmond, and Wetmore for further revision of the 

 ranges and other suggestions, after which, through the kind coop- 

 eration of Mr. Paul G. Redington, Chief of the Bureau of Biolog- 

 ical Survey, U. S. Department of Agriculture, it was submitted to 

 Dr. Oberholser who incorporated such additional information 

 as was contained in the extensive records of the Survey. The 

 chairman also examined the "general notes" in the last ten years 

 of 'The Auk,' 'The Condor' and 'The Wilson Bulletin' for pub- 

 lications of accidental or other occurrences that might have es- 

 caped the attention of the Committee. 



