Evolution 



339 



Fig. 108. — The fourteen species of Darwin's finches arranged to show their 

 evolutionary development. There are two chief groups, the ground finches of the 

 genus Geospiza, and the tree finches mainly of the genus Camarhynchus. The 

 ground finches are the more primitive. Of the tree species, i is a woodpecker-lilie 

 finch; 2 inhabits mangrove swamps 3, 4, and 5 are large, medium, and small in- 

 sect-eating birds; 6 is a vegetarian; 7 is a single species of warbler finch; and 8 



(Continued on opposite page.) 



