MUSEUM OF COMPARATIVE ZOOLOGY. 195 



primary, separated from the -white at the extreme tip by a broad space 

 of black. A subsequent gradual increase occurs in the purity of the 

 colors and in the extent and form of the wing markings. The complete 

 series of the changes in the latter is as fullows : At first, as previously 

 remarked, the primaries are dull brownish black, a little darker than the 

 general plumage, with their extreme apical margins lighter. At the 

 next stage the three inner primaries have become much lighter, and 

 the light border to all broader and whiter. Later the three inner pri- 

 maries and the distal portions of most of the others become wholly ashy 

 white, and the outer portion of the other primaries much blacker. The 

 subapical dark portion of the wing now embraces only the seven outer 

 primaries, and is of a triangular form, the first primary forming the base 

 of the triangle. The black on the outer vane of the first primary 

 reaches nearly to the base of the outer vane of the second, and is more 

 and more restricted on the others, till on the sixth (or, more rarely, on 

 the seventh) it forms only a narrow bar near the tip. In other words, the 

 black, if present on the seventh primary, exists as a narrow transverse 

 subapical bar, which bar increases in distal extension on the sixth, 

 fifth, fourth, third, and second, to the first, and embraces the whole 

 outer vane of the first primary. The basal outline of the black 

 area being an oblique one, a much larger portion of the outer than of 

 the inner vane of each feather is embraced in the black space. All the 

 primaries are now terminated with a narrow white border, the first pri- 

 mary having also an oval white spot on the inner vane, near the end of 

 the feather. Subsequently this spot enlarges so as to embrace a part of 

 both vanes, the white at the tip of the feather also meantime increasing 

 somewhat in extent, and the two being separated by a broad bar of black. 

 Coincident with this increase in the amount of white on the first primary, 

 a small white spot appears on the inner vane of the second primary. 

 Subsequent increase in the extent of these white markings goes on until 

 the white area on the second primary extends to both vanes, and the 

 two white spots on the first primary are separated by only a narrow 

 bar of black. Later still this bar becomes broken, through the partial 

 union of the two white' spots, and finally becomes entirely obsolete, 

 leaving the first primary with a single continuous white apical area, an 

 inch and a half to two inches in length. It is probable that not all 

 individuals reach this final stage, though most doubtless do in old age. 

 A large series of specimens of mature birds usually exhibit the gradual 



