Vol-^XXVIIj Brewster, The Red-legged Black Duck. 325 



Black Duck — giving them, however, in his own terms and in 

 nearly inverse order, and omitting altogether one which I had placed 

 almost at the head of the list and t(3 which I continue to attach much 

 importance — Dr. D wight presents his own evidence with which I 

 will now proceed to deal as briefly as possible. In the first place he 

 says that by skinning and dissecting "fully fifty specimens repre- 

 senting many localities, north and south, besides examining dozens 

 of others shot by friends or found hanging in the markets" he has 

 satisfied himself that the differences which I have considered of 

 subspecific significance "are exactly the ones that distinguish old 

 birds from young whether they occur in the United States or in 

 Canada." "A series selected from many fresh specimens sent me 

 [him] from Long Island, New York, shows that the Black Duck, 

 like many of the other ducks, slowly passes from the juvenal into 

 the first winter plumage, a change in the color of the feet and bill 

 taking place at the same time. The feet of grown young birds, 

 at first olive brown, become gradually reddened, and finally in the 

 spring they are of nearly as bright a red as that of the adults, while 

 the dusky bill brightens to greenish and then to yellow-green or 

 yellow\ . . . Once the adult colors of the soft parts are attained they 

 are never lost," the bill of the adult being "at all seasons of the year 

 a bright greenish yellow and the feet a coral red, these colors dulling 

 only a trifle after the breeding season." While some of the young 

 resemble adults, in respect to the color of the feet and bill, " as early 

 as January" others "are still dull in April," and "a very few 

 laggards in vitality seem to remain immature during their first 

 year." Immediately following these positive statements and in- 

 tended, apparently, to show on precisely what grounds they were 

 based — since no other evidence is mentioned — is the assertion that 

 " The bones, the trachea and larynx and the sexual organs proclaim 

 approximately the age of specimens carefully examined." This is 

 quite true in regard to young birds not more than five or sLx months 

 from the nest; but that it is equally true with respect to those which 

 have nearly or quite completed the first year of their existence I am 

 not at present prepared to believe, although my personal experience 

 in comparing the bones, sexual organs and other internal parts of 

 birds of many diftVrent kinds has perhaps been quite as extensive 

 as that of Dr. Dwioht. The matter has alwavs interested me, and 



