WE make use of plants in a great many ways, but the most 

 important way is as food for the sustenance of life of man 

 and beast. Among the most important parts of the plants used 

 for this purpose are the seeds and fruits. However, these terms 

 (fruit and seed} are very indefinite and should be used with 

 care. Fruits and vegetables are frequently confused; the to- 

 mato is usually spoken of as a vegetable, although the edible 

 part does not differ materially from many true berry fruits. 

 Botanically, a fruit is the ripened ovary, or the ripened ovary 

 with such other parts as may be united to it. However, some 

 fruits, such as the banana and the navel orange, have lost the 

 power to produce seeds and the fruit consists of only the ovary. 

 They are known as seedless fruits, and these plants must be 

 propagated by some of the non-sexual methods previously re- 

 ferred to. (Chapter VI.) Although we usually think of fruits 

 as being fleshy structures, the cotton boll, a gourd, a pepper 

 pod, or a bean pod are fruits as truly as is the peach or apple. 

 The seed is the mature ovule with its enclosed embryo, or as we 

 may have learned, the embryo with food supply and coverings. 

 The final result of plant energy is the production of its kind 

 and the distributing of its offsprings as far as possible. Each 

 species of plant, if uncontrolled by climate, water, soil, animals 

 and other plants would eventually tend to occupy the entire 

 earth. But many plants cannot spread beyond a certain limit, 

 because of the extremes of the climate; others are checked for 

 want of suitable soil ; others by bodies of water or desert plains ; 

 and still others by coming into competition with other plants 

 which are stronger and crowd them out. Man has taken advan- 



83 



