ECOLOGT OF FLOWERS 



365 



436. Movements of Floral Organs to aid in Pollination. 

 — Besides the slow movements which the stamens and 

 pistil make in such cases as those of the Olerodendron and 

 the mallow, already described, the parts of the flower 

 often admit of considerable and rather quick movements 

 to assist the insect visitor to become dusted or smeared 

 with pollen. 



In some flowers whose stamens perform rapid move- 

 ments when an insect enters, it is easy to see how directly 



II II 



Fia. 258. — Two Blowers of Common Sage, one of them visited by a Bee. 



useful the motion of the stamens is in securing cross- 

 pollination. The stamens of the laurel, Kalmia, throw 

 little masses of pollen, with a quick jerk, against the 

 body of the visiting insect. Barberry stamens spring up 

 against the visitor and dust him with pollen. The common 

 garden sage matures its anthers earlier than its stigmas. 

 In Fig. 258, A, the young flower is seen, visited by a bee, 

 and one anther is shown pressed closely against the side 

 of the bee's abdomen. The stigma, st, is hidden within 

 the upper lip of the corolla. In B, an older flower, the 



