FERTILIZATION. 



171 



the projecting stamens and receive pollen from them, as is 

 indicated in Fig. 154. 



209. Movements of Floral Organs to aid in Fertilization. — 

 Besides the slow movements which the stamens and pistil 

 make in such cases as those of the Clerodendron 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 movements 

 when an insect enters, it is easy tO' see how directly useful 

 the motion of the stamens is in securing cross-fertilization. 



Fig. 155. — Two Flowers of Common Sage, one of them visited by a bee. 



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 Mg. 155, 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 anthers have withered and the 

 stigma is now lowered so as to brush against the body of any 



