304 california academy of sciences. 



Genus Ammodramus. The Savanna Sparrows, etc. 



(1) Adult male like female; young more or less 

 closely resembling adult. 



Prevailing colors, black, white, brown, gray, buff, 

 yellow. 



This genus consists mainly of unspecialized streaked 

 species, although a greater degree of development is ex- 

 hibited in a few forms. Most of the species show yellow 

 either on the face and superciliary stripe or on the edge 

 of the wing, or sometimes in both places. What its 

 significance may be I will not attempt to suggest, for 

 although it may be the result of sexual selection it is 

 present equally in both sexes. Climatic influence has 

 played an important part in the differentiation of the 

 various races, particularly of the A. sandwichensis group. 

 The seaside sparrow (A. marithnus) has assumed a uni- 

 form coloration above, but the young are streaked like 

 typical members of the group. 



Genus Chondestes. The Lark Sparrows. 



(2) Adult male like female; young like some ances- 

 tral stage of the adult. 



Prevailing colors, black, white, brown, chestnut, 

 gray. 



Although not highly developed in color, the markings 

 of this genus are more specialized than any of the family 

 thus far considered. The complicated black pattern of 

 the head is to be looked upon as the combination of the 

 streakings of the primitive plumage into certain well 

 defined areas. These head stripes are probably recogni- 

 tion markings of some sort, but whether directive or 

 discriminative, is uncertain. The little spot of black 

 on the breast is of interest, being apparently the incip- 

 ient stage of a new character. The plumage of the 

 young points directly to a streaked ancestor in common 

 with most of the group. 



