THE COMPOSITtE 217 



In the florets of the DandeUon there are distinct notches 

 at the tips, indicating that five petals cohere to form the 

 corolla. 



The floral head of the Compositse is, then, a colony of 

 flowers, each one showing sympetaly, a reduction of 

 parts, and high specialization. The principle of co- 

 hesion of parts is here extended even to the stamens, 

 which are five in number, and usually joined by their 

 cuticles in such a manner as to form a tube. The anthers 

 open into the tube, shed their pollen therein, and this 

 vital dust is swept out of the tube and placed in a 

 position in which it can be picked up by insects by 

 means of the style of the pistil. The style acts as a 

 sort of tube brush. It sweeps out the pollen as it 

 extends in length. The calyx in the Compositse is 

 either reduced to feathered hairs or simple bristles, or 

 entirely suppressed. In many species it ultimately 

 forms the hairy faff us which crowns the seed, and 

 enables it to be transported by the wind to " fresh woods 

 and pastures new." 



The high specialization of the Compositse has not been 

 attained in vain, as is evident from the success of the 

 family in the struggle for existence, and the vast number 

 of existing species. They form about a ninth part of 

 all the flowering plants, and are represented in all parts 

 of the world, even in the extreme limits of vegetation 

 towards the Poles. For the most part they are herbs, 

 but there are tropical species which attain the propor- 

 tions of shrubs and even trees. The reader, however, 

 will have observed that eminence in the scale of life 

 does not consist in magnitude, but is evidenced by 

 specialization and adaptation to high uses. Man is 



28 



