234 BULLETIN OF THE 



are also of less extent in southern specimens. There hence results, as 

 already observed, a generally darker aspect in the plumage of the 

 southern representatives of wide-ranging species ; the bill and the feet 

 also usually sharing in the general accession of coloring matter in the 

 integuments. The difference in color between the extremely northern 

 and the extremely southern representatives of a given species is often 

 so great that, taken in connection with other differences, as in general 

 size and in the size and form of the bill, the two extremes might be 

 excusably taken for distinct species, especially if viewed aside from the 

 connecting series between the two types formed by specimens from suc- 

 cessively intermediate- points, which beyond question show their specific 

 identity. 



As in the case of climatic variation in the bill and in general size, 

 the variation in color differs greatly in degree in different species. 

 Climatic difference in color is particularly striking in Agelceas pharni- 

 ceus. In the males the black is greatly intensified and more lustrous 

 at the South, and the red on the shoulders becomes equally heightened. 

 Instead of the light red shoulder-patch, bordered externally with 

 whitish or pale yellowish-whitish, seen in Massachusetts specimens, the 

 shoulder-patch in the Florida males is of a brilliant dark red, with a 

 rich cream-colored or orange-yellow border. "While the differences in 

 the bills of the two types might in extreme cases be taken as indicative 

 of different sub-genera, the difference in color is as great as occurs 

 between the northeastern type of A. phce?iiceus, and either the so-called 

 A. tricolor or A. gubernator of the Pacific slope, or between any of these 

 ititer se. Quiscalus purpureus also affords a similar example of climatic 

 variation, as well in color as in the bill and general size. In the males 

 the change in general tint is in the black becoming more intense at the 

 South, and the iridescence being dark purple or bluish instead of bronzy 

 or greenish. The change in the females is as great as that in the 

 males. At the North their plumage is nearly lustreless brownish-black, 

 but at the South it becomes nearly as black as that of the northern 

 males, and has considerable iridescence, so that the northern collector, 

 judging from color alone, would at first be likely to mistake the south- 

 ern females for males. 



In Ortgx virginianus, through the increased breadth of the transverse 

 bars of hlack at the South, on the dorsal as well as on the ventral sur- 

 face, the general aspect of the plumage is very much darker in Florid? 



