82 SELF-POLLINATION 



pollen on various parts of its body. On the contrary, the 

 " Bee-flower " is so constructed that its honey cannot be 

 obtained unless the insect visits in a certain special manner; 

 the consequence is that the visiting insect receives pollen 

 on a certain definite region of its body, and may unerringly 

 convey that pollen to the stigma of the flower next visited. 

 For instance, in the pea-flower it is the under-surface of the 

 bee's body which comes into contact with the pollen and 

 stigma ; in the Foxglove, it is the back of the humble-bee 

 which is pollen-dusted and meets with the stigma. This ar- 

 rangement in these "Bee-flowers," therefore, not only allows 

 the flower to economise in pollen, but it also places the pollen 

 and honey in a position of greater safety in regard to the 

 injurious action of rain and the inroads of marauding insects. 

 For further illustrations, refer to Ranunculaceae (p. 121), 

 Papilionaceas (p. 138), Labiatae (p. 155), Scrophulariaceae 

 (p. 157), Caprifoliacese (p. 160), Araceae (p. 180). 



SELF-POLLINATION. 



Although in the case of many plants cross-pollination leads 

 to the production of better seeds, or more seeds, than self- 

 pollination, yet some plants produce quite as many seeds, 

 and those of as good quality, by self-pollination as by cross- 

 pollination. Cross-pollination has this advantage over self- 

 pollination, that it frequently affbrds a better crop of seeds. 

 But self-pollination is superior in one respect, it is easily secured 

 and rendered certain : the pollen simply has to come into 

 contact with a stigma which is ready and close at hand. 

 The self-pollinated plant is not dependent on the presence 

 of another individual -plant of the same kind in the im- 

 mediate neighbourhood : furthermore, it neither demands the 

 attendance of special insects nor the influence of wind in a 

 certain direction to carry the pollen to another individual. 

 Many flowers are self-pollinated, either spontaneously or by 

 the agency of insects. Insects wandering over the Buttercup- 

 flbwer frequently eiifect self-pollination. In Malva rotundifolia 

 (see page 134), and in some members of the Daisy-family, 

 the stigmas curl down until they reach the pollen -laden 

 anthers, so that the flower spontaneously pollinates itself. 

 The flower of the Poor-man's Weather-glass {Anagallis), if it 



