AMONG THE HEATHER. 113 



like effects have been produced in two hemi- 

 spheres on different tribes by the same causes. 

 The plain brown swifts of the North have 

 developed among tropical West Indian and 

 South American orchids the metallic gorgets 

 and crimson crests of the humming-bird : 

 while a totally unlike group of Asiatic birds 

 have developed among the rich flora of 

 India and the Malay Archipelago the exactly 

 similar plumage of the exquisite sun-birds. 

 Just as bees depend upon flowers, and 

 flowers upon bees, so the colour-sense of 

 animals has created the bright petals of 

 blossoms ; and the bright petals have reacted 

 upon the tastes of the animals themselves, 

 and through their tastes upon their own 

 appearance. 



