THE FLOWER AND THE BEE 



flower, snapdragon, and monk's-hood, while the nectar is so 

 carefully concealed that few insects besides the long-tongued 

 bees can obtain it. While in general all blue flowers are bee- 

 flowers, not all bee-flowers have bilabiate or irregular forms. 

 The gentian family contains many perfectly regular blue flowers 

 which are adapted to bees. The gentians are very abundant 

 in the Alps, and display great masses of vivid blue coloring. 

 Huxley, while seeking health in the bracing air of these moun- 

 tains, found great pleasure in studying these flowers, to an 

 account of which his last paper was devoted. The intensity of 

 their blue coloration has been well described by Bryant in 

 his lines to a fringed gentian (Fig. 43) : 



"Blue, blue, as^ if the sky let fall 

 A flower from its coerulean wall." 



In the Campannlacece there are 2^2 blue flowers which are 

 bell-shaped; while in the Compositse there are many species 

 in Avhich the heads have blue or purple rays, as in the autumnal 

 flowering asters. A preference for blue coloring shown by bees 

 does not necessarily imply that blue affords them an aesthetic 

 pleasure; but only that they recognize the signal of flowers 

 adapted to their visits. 



Purple Flowers 

 Red-purple flowers should be classed with red flowers, and 

 blue-purple flowers with blue flowers (Fig. 114); but in addi- 

 tion to these there are in northeastern America 134 dull or 

 lurid purple blossoms. Many of them are brownish or green- 

 ish purple, of small size and rarely visited by insects. Green- 

 ish-purple flowers which are the result of retrogression occur 

 in the milkweed family (Asclepiadaceoe) and Polygalacece. 

 From one to a few purplish flowers occur in a great number 



254 



