THE SURVIVAL OF THE FITTEST 



431 



FIG. 297. Lily 

 bulb. 



dried up by the fierce summer sun, or bitten 

 by frost, and are therefore not awakened to life 

 by the spring rains. 



The chances are often small that a seed will 

 fall into a safe place and will be free from 

 enemies. Although so many seeds are de- 

 stroyed, the average plant produces such large 

 numbers of them that enough survive to pro- 

 duce a growth of new plants. A healthy fox- 

 glove plant produces over one million seeds, 

 so that even with heavy losses, enough seeds 

 remain to guarantee plants in abundance. 



The worst enemies of sprouting seeds and 

 growing plants are overcrowding and starva- 

 tion. A plant needs water, air, food, and plenty of room. The 

 seeds and young plants which start their growth in crowded 

 places are too overshadowed by their close neighbors, too shut 

 off from air and sunshine, and too meagerly supplied with food 



from the ground to 

 develop into healthy 

 plants. Some seeds 

 are stronger than 

 others and can get a 

 start in spite of over- 

 crowding, of burn- 

 ing sun or bitter 

 cold, of too dry soil 

 or too wet soil or too 

 little soil (Fig. 298). 

 Plants which come 

 from hardy seeds 

 usually grow in spite 

 of unfavorable con- 



FIG. 298. These plants are growing in spite of 

 unfavorable conditions. 



