The Angiosperms 181 



for transportation through the agency of the wind 

 are extremely numerous, but will have to be passed 

 over here. As well as assisting in the pollina- 

 tion of flowers, animals are very important 

 agents in transporting the fruits, which may be at- 

 tractive to them as food, in which case the 

 enclosed seeds are thrown aside and scattered, 

 or are swallowed and pass through the body 

 of the animal undigested, and are ejected in the 

 excreta. Birds are especially important in this 

 distribution of seeds, owing to their rapid flight 

 and their long migrations, and doubtless many 

 widespread species of plants owe their distribution 

 mainly to bird agency. Other modifications asso- 

 ciated with the distribution of seeds through animal 

 agencies are the adhesive organs of seeds and fruits 

 by which they cling to the coats of animals and are 

 carried from place to place. 



Angiosperms Adapted to All Conditions of Life. 

 The many special modifications of the angio- 

 sperms, adaptations to all the varied conditions of 

 life, can only be touched upon here, but later will 

 be considered more at length. Among them there 

 are plants fitted to almost every possible condi- 

 tion under which plants can grow at all. While 

 reaching their most luxuriant development in the 

 hothouse conditions of the equatorial lowlands, they 

 can also grow at the very limits of vegetation in the 

 polar regions, or upon alpine summits ; under the 

 fierce sun of the desert, or completely submerged 



