448 Correspondence. YiuXy 



plumages known instead of unknown quantities will not solve zoological 

 equations and may produce astonishing results. Our ab's and xy's should 

 be recognized as such and kept separate, the former only being used in 

 final solutions and the latter put aside for future consideration and in- 

 corporation in the problem when increased knowledge justifies. Against 

 this there is the constant cry for exact information on the grounds that he 

 who examines material is best qualified to pronounce upon it. Exact 

 information is most desirable but we do not want to obtain an appearance 

 of it by disguising a guess as a verified fact. Of course when our own 

 knowledge or material fails there is always the alternative of submitting 

 the problem to "authority," but the question then is, what authority and 

 how far it should be accepted without verification. It may be admitted 

 that some specialists, through wide experience and specially developed 

 faculties, at times attain an almost uncanny intuition as to the identity of 

 specimens, and their opinions even where they fail to support them by 

 evidence convincing to others carry considerable weight, but we cannot 

 admit that the mere dicta of even such gifted mortals should be accepted 

 without reservation nor can their findings relieve the rest of us from the 

 responsibility. When such determinations are to be included in our 

 presentations they certainly should be given for just what they are, quota- 

 tions of others, and their source plainly indicated, not only that due credit 

 be given but to protect the writer and that the personality, experience and 

 viewpoint of the authority may be estimated by the reader. For this 

 purpose it seems to me the binomial heading and subspecific discussion in 

 accompanying text offers the most ample opportunities without violating 

 any of the vital principles of modern practice. 



P. A. Taverner, 

 Geological Survey, 



Ottawa, Canada, April 26, 1919. 



[Our "misunderstanding" of Mr. Taverner's practice is we think more 

 imaginary than real. When one sees a single Song Sparrow and being in 

 doubt as to its subspecific identity, uses the term Melospiza melodia, it 

 seems that he is using the term for "some one race" just as stated in our 

 previous note. In many cases too he uses the binomial heading with no 

 subspecific discussion whatever in the text, which is the practice that we 

 particularly criticised. However, this is a trivial matter. We understand 

 and are in sympathy with Mr. Taverner's desire to record facts and not 

 guesses, but we still consider that his method is confusing and the use of 

 "subsp? " is necessary if his meaning is to be made clear to the great bulk 

 of readers. The number who do not yet understand the A. O. U. plan as 

 practised in the last edition of the 'Check List' is vastly greater than Mr. 

 Taverner imagines. They still think that every binomial indicates one sort 

 of bird! 



By introducing a sj'stem of this sort, which only a few are likely to follow, 



