° 1912 J Towt^sEND, Red-legged Subspecies of Black Duck. 177 



to the study of the subject. I have made no observations on the 

 adult male breeding bird in summer in Essex County, and as far as 

 I know this has never been done. Its ^ alue in the discussion is 

 obvious." I should have added that as the female often assumes 

 masculine characters with age, it is possible that this fact may 

 explain the existence of female nibripcs. From the data then at 

 hand, I believe that my position was a logical one, and that one 

 could argue both for and against the validity of rubripes as a sub- 

 species. The proofs were still lacking. 



In July, 1908, the fourteenth supplement of the A. O. U. Check- 

 list was published in which the name ^inas obscura was changed to 

 Anas rubripes, and the following statement made: "The name 

 Alias obscura Gmelin, 1788, proves to be preoccupied by Anas 

 obscura Pontoppid.\n, 1763, for an old world species, and no other 

 name being available, rubripes of Brewster is adopted as a substi- 

 tute. (Richmond, ms.) There is some question as to the validity 

 of the form recognized as No. 133a, [the Red-legged subspecies of 

 Brewster] which, by the above action, is now cancelled." 



Notwithstanding this statement of skepticism as to the validity 

 of the two races, the next supplement, published in July, 1909, 

 admits its belief in them by recognizing Anas rubripes tristis or 

 Black Duck on the basis of a paper on the subject by Mr. Brewster 

 in the previous April, in which, how^ever, no new facts are adduced. 



In October, 1909, Dr. Jonathan Dwight maintained that the 

 differences between the supposed races were "exactly the ones 

 that distinguish old birds from young whether they occur in the 

 United States or in Canada" and he added that his evidence on 

 this point was "conclusive." 



To this Mr. Brewster replied in July, 1910, and showed that none 

 of Dr. Dwight's evidence was conclusive, and that the only breeding 

 bird examined by Dr. Dwight, shot on Long Island, might easily 

 have come originally from the Bronx or Central Park. 



Thus by the whirligig of time and the A. O. U., the Black Duck, 

 so long and familiarly known as Ajias obscura, becomes a sad sub- 

 species of the upstart Red-leg, and even then its position is disputed, 

 while the erstwhile Red-legged subspecies is put on a secure specific 

 basis. One is forcibly reminded of the behavior of the intruding 

 Cow-bird. The title of this paper should therefore have been 



