242 



GENERAL BIOLOGY 



of the Hawaiian field, without competition except among 

 its own members, appears to have been developed along 

 many divergent lines in adaptation to all the natural func- 

 tions that are fulfilled by all the families of the order 

 elsewhere; and there are stout seed-cracking finch-like 



FIG. 150 Swift and swallow (drawn for this book by Mr. L. A. Fuertes). 



beaks, and slender leaf-searching warbler-like beaks, and 

 many other forms of beaks possessed by the different 

 members of the one family. A like diversity of group 

 development upon a larger scale is found among the 

 pouched mammals (marsupials) of Australia, and another 

 example among the cat fishes (Siluroids) of South America. 



