tube, while the pin-headed summit of the pistil only 

 reaches just half way up the tube, exactly opposite the 

 same spot where the stamens are fixed in the other sort. 

 When the bee begins by visiting a thrum-eyed blossom, 

 she collects a quantity of pollen on the hairs at the top 

 of her proboscis. If she then visits a second flower of 

 the same type, she does not fertilize its pistil, but only 

 gathers a little more pollen. As soon, however, as she 

 reaches a pin-eyed blossom she unconsciously deposits 

 some of this store of pollen on the sensitive surface or 

 pin of its pistil ; while at the same time some more 

 pollen, half way down the tube, clings to her proboscis, 

 and is similarly rubbed off against the pistil of the next 

 thrum-eyed blossom she chances to visit. The exact cor- 

 respondence in position of the various parts in the two 

 diverse forms admirably insures their due impregnation. 

 Thus each blossom is not only fertilized from another 

 flower, but even from a flower of an alternative type, 

 which is a peculiarly high modification of the ordinary 

 method. 



