The Root and the Soil. 65 



of flowers and seeds, withholding the remainder for 

 nourishment through the winter and to develop leaves 

 the following spring. The reserve food in dormant cut- 

 tings (358) enables them to form roots and expand 

 their buds. 



SECTION VI. THE ROOT AND THE SOIL. 



With the out-door cultivator, the part of the plant 

 environment that lies beneath the soil surface is more 

 under control than the part that lies above it. He can 

 do little to change the composition or temperature of 

 the air or the amount of sunlight; he may do much to 

 influence the fertility, the texture, the drainage and the 

 aeration of the soil. A knowledge of the roots of 

 plants and of the soil in which they grow and feed, is, 

 therefore, of the utmost practical importance. 



86. The Office of the Root. The roots of laud plants 

 serve (a) to anchor the plant in the soil, enabling the 

 stem or stems of erect species to grow upright, and (b) 

 to supply the plant with water with its dissolved food 

 materials (62). 



87. The Root Originates in the Stem. As we have 

 seen, the primary root develops from .the lower or 

 "root-end" of the hypocotyl (44). But lateral roots 

 may develop freely from other parts of the stem. If 

 we examine the base of the stem of a plant of Indian 

 corn a few weeks after planting, we may see that the 

 main roots start above the point at which the stem was 

 originally attached to the seed; and if we pull up a 

 pumpkin vine or an untrellised tomato plant late in 

 summer, we often find it rooted from the stem at some 

 distance from the original root. Lateral roots originate 



