Fig. 70. An alpine willow, showing a strong rootstock developing aerial branches 

 and roots, and capable of long life and extensive migration.— After Schimper. 



itself into such relations that 



Fig. 71. A flower of peony, showing the four sets of 

 floral organs : k, the sepals, together called the 

 calyx ; c, the petals, together called the corolla ; 

 a, the numerous stamens ; g, the two carpels, 

 which contain the ovules.— After Strasburger. 



it may secure pollination. 

 Besides pollination, 

 which is necessary 

 to the production of 

 seeds, there must he 

 an arrangement for 

 seed distribution. 

 It is always well for 

 seeds to he scattered, 

 so as to be separated 

 from one another 

 and from the parent 

 plant. The two 

 great external prob- 

 lems in connection 

 w i t h the no w e r , 

 therefore, are polli- 



