Plants as Living Things 9 



Reproduction an essential process in plant life. To be success- 

 ful, plants must not only maintain themselves, but in addition 

 they must provide for the continuation of similar plants in the 

 future ; for plants maintain their kind from year to year and from 

 one century to the next by producing new plants like themselves. 

 Reproduction is sometimes accomplished by the separation and 

 further development of a part of the parent body, as the tuber of 

 a potato or the runner of a strawberry plant. In most plants, 

 however, it takes place also through the development of seeds, 

 and it is upon the growth of the young plant within the seed that 

 the production of another generation of that particular kind of 

 plant depends. A sunflower may develop a tall stem and a large 

 leaf area, but unless it flowers and produces seed, no young plants 

 will be grown from it. If it were the only sunflower in existence, 

 there could be no more sunflowers after its death. Reproduction 

 in plants must, therefore, be considered as an essential process, 

 for without it plant life would soon disappear from the earth. 



Summary. Plants are not nearly so complicated as the higher 

 animals. Nevertheless, in the course of their long history on 

 the earth, the plant body has become differentiated into several 

 rather distinct organs which differ from each other in structure, 

 and each of which carries on quite a different group of physio- 

 logical processes. Roots, stems, and leaves are the chief organs 

 of nutrition. Flowers, fruits, and seeds are the organs concerned 

 with the reproduction of the plant. Each organ of a plant is 

 more or less dependent upon the other organs, and the plant 

 attains its greatest development only when all the organs are 

 working in harmony together. This is possible only when each 

 of the organs is placed in favorable conditions. 



