. ANIMALS AND PLANTS 249 



dark. A flowering vine of white honeysuckle, or a bush 

 of the pale yellow evening primrose, may often be seen 

 at dusk to be swarming with great sphinx moths, which, 

 poised before the flowers like humming-birds, probe the 

 deep, narrow trumpets with their long tongues. Pass- 

 ing from flower to flower in their search for honey, 

 cross-pollination is almost certain to be effected. 



While the chief agents in the pollination of flowers 

 are insects, especially butterflies and bees, other ani- 

 mals also may be of importance in this connection. It 

 is said that snails have been observed to convey pollen 

 from the flowers of some aroids, but next to insects it 

 is birds which play the most important r61e, especially 

 the peculiar American group of humming-birds, which 

 are preeminently flower visitors. Although in north- 

 eastern America there is but a single humming-bird, 

 the little ruby-throat, several of the native flowers seem 

 to have adapted themselves especially to its visits. 

 Among the most striking of these humming-bird flow- 

 ers, are the coral honeysuckle, cardinal flower, trumpet- 

 creeper, crimson balm (Monarda), and wild columbine. 

 All of these have deep, narrow nectaries, and scarlet 

 is the predominant color. Of the garden flowers, 

 which are especial favorites of the humming-birds, 

 may be mentioned the various species of Canna, fuch- 

 sia, nasturtium (Tropoeolum), and the scarlet Mexi- 

 can sage. In California the fuchsia-like Zauschneria 

 and the crimson-flowered currant (Ribes speciosum), as 

 well as a number of other bright red flowers, are eagerly 

 sought by the native humming-birds. It will be noted 

 that nearly all these flowers are vivid red, a color which 

 appears to be especially attractive to these little birds. 



