How Plants Live 27 



materials they need, (3) what they take out of the air, 

 what they give off into the air, and how they do this, 

 (4) what advantage they have in being green, (5) how 

 they may be protected from their enemies, and (6) how 

 they may be grown to yield especially early crops or 

 crops of unusually fine quality. 



This knowledge of how plants live and grow has now 

 become a science, and an understanding of this science 

 is of the greatest help to the gardener in his work. For 

 knowing how plants live makes it more interesting to 

 work with them, and the scientific gardener can care 

 for his crops far more intelligently and supply their 

 needs far better than one who does not understand the 

 reasons for what he does. In the following para- 

 graphs, therefore, we shall explain how a plant lives. 



The parts of a plant. Let us examine some garden 

 plant, such as a bean or a corn plant. We notice that 

 it is composed of a stem and leaves which grow upward 

 into the air, and of roots that are in the soil. 



Now let us look at a young radish about ready for 

 table use. At first glance its leaves appear to grow 

 directly from the roots. But careful examination shows 

 that there is really a short stem between the leaves and 

 the main root; and when the plant shoots up into 

 flower, we see that it has the same parts as the bean 

 and corn and other plants that we grow in our gardens. 

 Much as garden plants differ in form and appearance, 

 they are all alike in having (i) leaves that are exposed 

 to the air and sunshine, (2) roots that burrow in the earth 

 and darkness, and (3) a stem connecting the roots with 

 the leaves. 



