'Blossom Hosts and Insect Gnests 



moss, clothed in royal purple, and surrounded by 

 groups of gayly attired, fluttering admirers. 



The blue-flag is a conspicuous example of a flower 

 which has guarded itself against self-fertilization and 

 which is beautifully calculated to secure the oppo- 

 site result. 



In most flowers, with the exception of the or- 

 chids, the stamens and pollen are plainly visible ; 

 but who ever sees the anthers of the blue-flag? 

 Surely none but the analytical botanist and the 

 companion insect to whom it is so artfully adjusted 

 and so demonstrative. This insect is likely to be 

 either a bumblebee or a species of large fly. 



In apt illustration of Sprengel's theory of the 

 *' pathfinder," the insect does not alight at the cen- 

 tre of the flower, but upon one of the three large 

 drooping sepals, whose veins, converging to the nar- 

 row trough above, indicate the path to the nectar. 

 Closely overarching this portion is a long and narrow 

 curved roof — one of three divisions to the style, each 

 surmounting its veined sepals. Beneath this our 

 visiting bee disappears, and a glance at my sectional 

 drawing shows what happens. Concealed within, 

 against the ridge-pole, as it were, the anther awaits 

 his coming, and in his passage to and from the nec- 

 tar below spreads its pollen over his head and back. 



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