A 3 2 Recent Literature. \j^x 



or the size of particular parts, as the bill, wing, tail, tarsus, etc., in closely 

 related species is often much less than the range of purely individual vari- 

 ation in any one of the several species that may be involved ; and where 

 color at the same time may fail, as happens in some grouDS, even the 

 expert is sorely puzzled to discriminate between museum specimens of 

 species that in life are at once recognizable as distinct by their notes, 

 habits, pose, and almost every act and attitude, as in the case of some of 

 the species of the genus Empidonax. Thus an expert confessed to me 

 that on one occasion when he came to label up his season's collecting he 

 found that in order to tell ' tother from which ' in the case of two per- 

 fectly distinct species of Empidonax he had to resort to dates of collecting 

 and his notes on the living birds entered in his notebook to decide which 

 was which ! The present writer once had also a similar experience. Yet 

 it is not quite impossible nearly always to recognize these closely related 

 forms — good species, not subspecies — without recourse to notes on the 

 living bird. Much more might be said anent "Principle 2"; but inas- 

 much as many species that no one could confound in life would be ruled 

 out by the "five per cent." rule, it is hardly necessary to say more. 



"j. Characters -which cannot be recognized tuithout knowledge of the 

 geographical origin of the specimen ought not to be made the basis of a 

 new name. . 



"This is a very essential principle if we agree that an important end of 

 systematic zoology is correct knowledge of the geographical distribution 

 of animals. It seems to me axiomatic that characters which cannot be 

 recognized regardless of the locality where the specimens are collected 

 are worthless, yet Dr. Allen holds to the contrary, and regards my sup- 

 port of this principle as evidence of my writing without possessing the 

 necessary familiarity with the facts. The horned lark from Mexico 

 named Otocoris alpestris ckrysol&ma by Oberholser differs from the 

 same author's subspecies actia so slightly that he himself admits they 

 are indistinguishable, unless the locality where collected is known. I am 

 unable to see what possible gain there is in giving a name to such a 

 form ; while christening it may easily lead to serious errors in deter- 

 mining the geographical distribution of the real subspecies of horned 

 larks. And in all other groups of animals, the confusion of special 

 geographical position with essential morphological character leads, and 

 always will lead, to most erroneous conclusions concerning the distribu- 

 tion and history of species. A well known American mammalogist is 

 said to hold the view that any mammal resident on an island must nec- 

 essarily be a different subspecies from the form on the neighboring 

 mainland, because of its isolation. If such views are current among 

 systematists, (which I greatly doubt), it is not strange that morpholo- 

 gists, physiologists and embryologists have long held systematic zoology 

 in contempt, and even now regard with suspicion our claims to a place 

 among the real devotees of science." 



Respecting ' Principle 3 ' little need be said, either in its favor or 



