128 LUTHER BURBANK 



Many other flowers show equal or greater in- 

 genuity. 



In some varieties of the sage, the pollen-bear- 

 ing stamens actually descend and quickly rub 

 the yellow dust on either side of the insect, after 

 which they fall back into their former position 

 above the nectar cells. 



The orchids, almost without exception, show a 

 most marvelous ingenuity. 



Some of the species bear their pollen in small 

 bundles, the base of each bundle being a sticky 

 disk. The structural arrangement of the flower 

 is such that the insect cannot secure its nectar 

 without carrying away at least one of the 

 bundles. A pollen bundle glues itself to the 

 head of the insect and curves upward like a horn. 



As soon as the insect has withdrawn from the 

 flower, this pollen horn bends downward in 

 front of the insect, so that when the next flower 

 is entered the dust can hardly fail to reach a 

 receptive portion of the stigma. 



In these orchids there are but single receptive 

 stigmas and the pollen bundles are separate and 

 single also, but in another orchid which has two 

 receptive stigmas, the pollen bundles are in 

 doublets, held together with a strap. 



Thus the insect visiting this second orchid 

 carries away two pollen bundles on its forehead. 



