AND CROSS-FEKTILIZE THEIR FLOWERS. 33 



now begin to understand the meaning of. It is turned to account in fertilisa- 

 tion. The six stamens surround a pistil, but diverge away from it, as if to be 

 sheltered, one under each of the concave or arching petals. There 

 they remain unless touched, as with a pin or any other body, at the 

 base of the filament on the inside ; then the stamen starts forward 

 suddenly, as with a jerk, into an erect position. Not far enough for- 

 ward, however, for the anthers to hit the stigma ; indeed, the filament 

 is not quite long enough for that. Now the anther opens in an un-- 

 usual way, namely, by trap-doors, one on each side (as shown in Fig. 

 25), letting the poUeu drop out. Barberry-blossoms are visited by ^'s- ^S- stamen 

 honey-bees and by smaller flying insects ; in the common Barberry the anther open- 

 flowers are hanging. A touch by the proboscis of a bee hovering un- '"b ^^ '"^P" 

 derneath causes the stamens in turn to spring forward suddenly, and to.- 

 shower the insect plentifully with their pollen. Some of this may be applied im- 

 mediately to the button-shaped stigma of that very flower ; but some would 

 surely be carried to the stigma of the next flowers visited, and so on. In species 

 with upright flowers, the pollen will dust the proboscis and head of the bee, or 

 of smaller insect crawling to the bottom for the nectar there ; and in entering a 

 subsequent blossom it must needs brush this pollen against its stigma. 



67. In Kalmiil (American Laurel, and equally in the smaller species, namely. 

 Sheep Laurel or Lambkill, and in the earlier-flowering Glaucous Laurel of the - 

 bogs), a mechanical instead of a vital movement is turned to similar account. 

 The singular structure of the blossom has long been known ; the operation of it 

 is only now understood. 



68. This is the plan of it. Ten stamens with slender filaments surround a 

 still longer style : the tip of the style is the stigma, which the pollen is somehow 

 to reach. But the anthers in the flower-bud lie in as many pouches in the sides 

 of the corolla (Fig. 26). When the corolla opens and takes its saucer-shaped 

 form, the anthers remain lodged in the pouches, so the filaments are bowed back 

 and become so many springs (Figs. 27, 28). If untouched the springs generally 

 remain set until the corolla begins to fade : by that time the filaments lose their 

 elasticity and become flabby also. If we jostle them, however, by- a somewhat 

 rude touch when the flower is in fresh condition, so as to liberate the anther, the - 

 filaments straighten elastically and suddenly, and generally curve over in 

 the opposite direction. As they fly back they discharge a quantity of pollen. 



