iSpi.J Brewster on Bachiua7i's Warbler. I^y 



biiils it is pale or obscured witli dusky olive, in others rich and 

 pure ranging froni deep lemon to light gamboge, which, how- 

 ever, in the brightest specimen before me does not quite equal 

 the coloring represented in Audubon's much criticized phue. 

 The yellow sometimes spreads over the entire abdomen and also 

 tinges the sides, flanks, and cris&um, but in the dullest birds it is 

 confined to the breast and a narrow central space on the fore 

 abdomen, the remainder of that part, with the crissum and Hanks, 

 being ashy white more or less sufliised with smoke-gray. There 

 is apparently no correlation between the extent of the black on 

 the jugulum and throat and that on the crown, nor between the 

 amount or purity of black on either or both of these parts and the 

 depth of the yellow. Thus the bird with the largest crown patch 

 has most of the throat yellow, and the one in which the craxat is 

 best developed has an exceptionally small amount of black on the 

 crown, while neither is among the specimens which are most richly 

 colored in respect to the yellow of the imder parts. The vellow 

 frontal band is fairly uniform in color, but is twice as wide in some 

 birds as in others. 



We collected ten females. Of these the brightest is practically 

 indistinguishable from the dullest male when the two are placed 

 side by side on their backs, for in the general coloring of their 

 underparts they agree very closely, much better in fact than does 

 the male with an}- of the other examples of its own sex. This 

 female, however, has a trifle less black on the jugulum and only 

 a little concealed black spotting on the crown, but another which 

 shows only a very little black on the jugulum possesses a band of 

 exposed dusky spots on the crown. The most constant and evident 

 sexual character seems to be the presence of a clearly outlined 

 yellow frontal band in the male and its absence in the female. In 

 all the males which I have examined this band is conspicuous and 

 well defined. Many females, it is true, have the forehead tinged 

 with yellowish or olive, but this is merely a sufiusion, not a pure 

 color, and in its extension backward it invariably shades insensibly 

 int(j the color of the crown instead of l)eing separated from the 

 latter by a distinct line of demarcation. It should be stated, how- 

 ever, that I have been able to appl} this test only to spring speci- 

 mens and that it may fail with the young in autumn plumage.* 



*Audubon states that the female is "considerably smaller than the male," but our 

 specimens show that there is only a slight average difference in this respect. The 

 largest females are decidedly larger than the smallest males. 



