1911] GrumcJl: The Linnet of the Hawaiian Islands. 181 



In an old male in the midst of the annual molt (for instance, 

 no. 1456H, taken August 9) we find presented side by side, very 

 brilliant but old and worn feathers, along side of dull carmine, 

 but new and unabraded feathers. 



Microscopical examination of various appropriate feathers 

 shows the following conditions. In the newly-acquired, unworn 

 feather, the red pigment is restricted to the barbs of the contour 

 portion of each feather, except for their terminal portions to a 

 distance of one millimeter from their tips. These barb-ends, 

 which together thus constitute a grayish band terminating each 

 feather, and all the barbules, are white. In the extremely old 

 abraded (summer) feather these uncolored end-portions of the 

 barbs in the overlapping feathers, and all of the barbules, have 

 simply been broken off and lost, thus removing the grayish 

 obscuration from the bright red in the barbs. The intrinsic 

 color of these has not changed one whit in tone or tint. For a 

 discussion of similar processes in other birds, see Dwight (1900, 

 pp. 73-360). 



One is again led to remark upon the difference in structure 

 between the pigmented and unpigmented portions of the feather, 

 the former being by far the most resistant, the latter being so 

 adjusted in extent, location and texture as to become completely 

 disintegrated and lost at the end of the winter season and at 

 the advent of the season of mating. 



As above explained, the apparent great range of variation in 

 color in a normal series is largely dependent on season, and is 

 due to wear; and when in each case this factor is given due 

 weight, it is found that the crimson type of coloration in the 

 California linnet is really quite constant. However, throughout 

 its range there occur, though in most regions rarely, individuals 

 of totally different appearance. 



Taking all available skins into consideration, it appears that 

 the colored parts of male linnets, always taking the wear factor 

 into account, fall into the following color categories: pure red 

 (crimson) ; pure yellow (chrome) ; orange (which is a blend of 

 these two colors) ; mixed (crimson feathers with yellow or orange 

 feathers scattered among them). 



The 307 males examined and tabulated (Table I), are from 



