EVOLUTION OF THE COLORS OF BIRDS. 153 



exclusiveljr white and eight other species in which it 

 figures as the prominent color. Among nearly all North 

 American genera some white is present, and in a large 

 proportion of species. When occurring in large masses 

 it is usually on the breast and under parts, as previously 

 intimated. It generally persists longest on the abdomen 

 and under tail coverts. Plate XIX of the genus Den- 

 droica furnishes illustrations of the way in which the 

 color fades out into white on the under tail coverts. I 

 know of no instances in which large masses of white 

 occur upon the upper surface of the body except such as 

 the bobolink and a few others in which the under parts 

 are largely black. 



The only North American species which is exclusively 

 red is the summer tanager (Piranga rubra). In the fol- 

 lowing species red is the prevailing color: 

 Pyrocephalus rubineus. Leucosticte . 



Pinicola. Gardinalis. 



Uarpodacus. Piranga erythronielas. 



Ergaticus ruber. Piranga hepatica. 



Two classes of red birds may be distinguished — those 

 in which the color occurs in clear, well defined patches 

 as in Pyrocephalus, Piranga and Gardinalis, and those 

 in which the plumage is everywhere suffused with red, 

 but the color not sharply marked out, as in Pinicola, 

 Carpodacus and Leucosticte. Carpodacus is more or less 

 intermediate between these two styles. When pure red 

 is present in smaller amounts it generally occupies well 

 defined local areas. Red crests are frequent, i. e., in most 

 of the woodpeckers where the color sometimes spreads 

 over the entire head as in Melanerpes erythrocephalus . 



Among the species having a crest of scarlet or some 

 bright red may be mentioned Milvulus forficatus, 

 Tyrannus verticalis, Passcrina versicolor, Acanthis and 

 Regulus calendula. Red or rose colored throat patches 



