PLANTS DEFEND THEMSELVES 35 



struggling against the stronger; the stronger mer- 

 cilessly crushing the weaker. The contention 

 among plants is bitter and frequently cruel. In 

 addition, they must survive the ravaging onslaught 

 of the all-destroying human kind. The extent to 

 which they progress in overcoming these obstacles 

 marks their success or failure in the struggle of 

 life. 



The habitat of plants largely decides their type 

 of difficulties and dangers. Thus the air plant is 

 immune from the pests which force the desert plant 

 to protect itself with daggers and prickles ; aquatic 

 plants rarely are troubled with creeping, wingless 

 insects or burrowing grubs; arctic plants, such as 

 mosses and lichens, need no defence against moths 

 and tropical pests ; while plants like dandelions and 

 milkweeds, which send their children out into the 

 world by means of airships and balloons, have no 

 fear of city congestion. So all plant life, as all 

 animal and human life, has been wisely created, 

 protected from certain dangers by its environment, 

 and provided with a means of defence against those 

 other dangers to which its environment subjects it. 

 For none is the burden made too heavy; for all is 

 the necessity to struggle in order to grow and live. 

 In the plant world as in the human world there is 

 a law of compensation. 



