48 



NATURE SKETCHES IN TEMPERATE AMERICA 



That some strange pollen grains are found entangled upon 

 the bird is not surprising, especially in the spring. Taking all 

 these suggestions into consideration, what wonder is it that 

 we are called upon to say that the phenomenon of so wide- 

 spread a means of pollination of plants by the humming-bird 

 is perhaps unparalleled. 



In conclusion it may be said that some colors of flowers 

 serve to make them visible and easily recognizable by insects, 

 which are attracted thereto by the secretion of nectar and pollen. 

 White flowers are nearly always excessively fragrant and are 

 visited by night-flying insects. Bird flowers which have 

 almost no fragrance, usually secrete an abundance of honey, 

 are bright colored, and are visited in daytime by humming- 

 birds. Both forms of these flowers seem to blossom at a time 

 when their guests appear in greatest abundance. 



Male Ruhii-throatcd Humming-bird 

 {Trochilius colubris). 



