116 



LIVING PLANTS 



nature. As the food suppl}^ is lessened, a 

 greater effort is made on the part of the 

 parent plant to enhance the chances for 

 perpetuity ; but at the same time the largest 

 seeds, having the greatest potentiality, stand 

 the best chance in the future struggle; and 

 although the best nourished plants produce 

 the fewest seeds, their greater size gives them 

 decided advantages over seeds from starved 

 plants. The two laws acting together, there- 

 fore, aid in maintaining the perpetuity of the 

 species and its full measure of vigor. 



TABLES. 



I. Yield of Wheat on Fertilized and Unfertilized 

 Ground. 



f Weights calculated to the acre.) 



