260 HOW CROPS GROW. 



Rootlets. — This term we apply to the slender roots, 

 but a few inches long, which ai-e formed last in the 

 order of growth, and correspond to the larger roots as 

 twigs correspond to the branches of the stem. 



The Offices of the Eoot are threefold : 



1. To fix the plant in the earth and maintain it in an 

 erect position. 



2. To absorb nutriment from the soil for the growth 

 of the entire plant, and, 



3. In case of many plants, especially of those whose 

 terms of life extend through several or many years, to 

 serve as a store-house for the future use of the plant. 



1. The Firmness with which a Plant is fixed in 

 the Ground depends upon the nature of its roots. It 

 is easy to lift an onion from the soil ; a carrot requires 

 much more force, while a dock may resist the full 

 strength of a powerful man. . A small beech or seedling 

 apple tree, which has a tap-root, withstands the force of 

 a wind that would prostrate a maize-plant or a poplar, 

 which has only side roots. In the nursery it is the cus- 

 tom to cut off the tap-root of apple, peach, and other 

 trees, when very young, in order that they may be readily 

 and safely transplanted as occasion shall require. The 

 depth and character of the soil, however, to a certain 

 degree influence the extent of the roots and the tenacity 

 of their hold. The roots of maize, which in a rich 

 and tenacious earth extend but two or three feet, have 

 been traced to a length of ten or even fifteen feet in 

 a light, sandy soil. The roots of clover, and especially 

 those of alfalfa, extend very deeply into the soil, and the 

 latter acquire in some cases a length of 30 feet. The 

 roots of the ash have been known as much as 95 feet 

 long. {Jour. Roy. Ag. Soc, VI, p. 343.) 



2. Root-absorption. — The Office of Absorbing 

 Plant Food from the Soil is one of the utmost impor- 

 tance, and one for which the root is most wisely adapted 

 by the following particulars, viz. : 



