Environment and Adaptation 235 



In his studies of the ornithophilous flowers of 

 South Africa, Scott-Elliot calls attention to the pre- 

 ponderance of bright recj or orange color in the 

 flowers which are frequented by the sun-birds. 

 These belong to often widely separate families, both 

 monocotyledons and dicotyledons. He states, also, 

 that there seems to be a relation between the color 

 of the birds and that of the flowers, the red color 

 in the species of Cinnyris, a genus of honey-sucker, 

 being almost exactly identical with the shade of red 

 found in a majority of the ornithophilous flowers. 

 I have seen myself, in South Africa, the sun-birds 

 visiting the scarlet Erythrinas and Aloes, and Scott- 

 Elliot gives a long list of other similarly colored 

 flowers which are frequented by these birds. In 

 their small size and colors, many of these sun-birds 

 recall strongly the iridescent American humming- 

 birds, although they are not at all related. 



While we may hesitate to accept all the conclu- 

 sions of the enthusiastic students who first realized 

 the immense importance of insects in the pollina- 

 tion of flowers, there seems to be no reason to doubt 

 that the course of evolution of the two largest 

 groups of animals and plants, insects and angio- 

 sperms, has been powerfully influenced by the mu- 

 tual adaptations that have arisen in these two groups 

 of organisms. 



