1911] Grinndl: The Liiniet of the Hawaiian Islands. 185 



region supports this belief ; for they show no apparent differences 

 in length of wing, in length of tail, in size or turgidity of bill, 

 or in intensity or extent of hair-brown streaking in either sex. 

 The only difference is in the color of those parts in the males 

 which arc colored. There is no perceptible increase or decrease 

 in the deposit of dark pigment in the females. 



It would appear that the hair-brown pigment and the red- 

 orange-yellow pigment are of different orders as regards modi- 

 fieational behavior. The latter does not appear to show at all 

 any response to humidity or to light-intensity, as does the dull, 

 browu-gray-ocher category of colors, which are subject to such 

 enormous range of shade and tint in a multitude of bird species 

 under varying climatic conditions. 



Of eighteen males of C. frontalis taken on the deserts border- 

 ing the lower Colorado River, in Arizona and California, about 

 the most arid region of North America, February 22 to April 80, 

 and therefore comparable in stage of wear with the Hawaiian 

 series, all but two are of the crimson color type, and uniform, 

 accounting for results of greater w^ear in the latest spring 

 examples. The characteristic color is dull crimson tending 

 toward burnt carmine, this spreading over the whole dorsum and 

 sides of head. Wear brightens this toward poppy red. Of the 

 two aberrant examples in this lot, one is quite uniform orange- 

 vermilion (and thus nearly a duplicate of the deepest orange of 

 the Hawaiian birds, no. 12602) ; the other is dingy chrome yel- 

 low, not exactly like any of the Hawaiian examples, but of the 

 same general category as nos. 12598 and 12613. There are no 

 birds of mixed colors in this lot. Thus 11 per cent, of this lot 

 of desert linnets are "off color," and 6 per cent, each are of the 

 distinctly yellow type and the orange-red type. 



According to ^McGregor (1901, p. 13), linnets from certain 

 islands off the west coast of Lower California are notably subject 

 to this color variation. "Among the finches from the San Benito 

 Islands (C. mcgregori), I have never seen two alike. The colors 

 range from bright crimson through orange into lemon yellow, 

 with all manner of variations resulting from combinations of 

 these colors and their shades and tints. It is impossible to take 

 any example and say it is the typical coloration. 



