46 THE PLANT: A GENERAL EXTERNAL VIEW 



total length of the root is often much greater than the total 

 length of the stem and all its branches. The total length 

 of all the roots of an ordinary corn plant is several hundred 

 feet. 



Think of the deKcate root of a young plant as it first 

 begins to burrow into the soil. Pull it up gently, brush 

 off the soil grains carefully, and you find 

 a tip as soft and tender as a baby's finger. 

 Little here that suggests great power to 

 dig ! The smooth surface is broken only 

 by a delicate fuzz of fine hairs. They are 

 just behind the tip. Unless you have been 

 very careful, these root-hairs have been 

 broken off. (See Figure 2.) This delicate 

 root tip has a remarkable power. It has 

 the power to penetrate stiff soil, to bur- 

 row deep below the surface. Sometimes 

 even hard rocks are found broken by the 

 gradual work of roots. 

 Fig. 2. -a young The Structure and the position of roots 



root tip of corn. i i . 



suggest to US the things which they do. 

 These principal functions of roots are to get from the soil 

 those things necessary to the life of the plant which are 

 found in the soil, and to hold the plant firm. The 

 entire root system holds the plant firm, but only the 

 young and tender parts do the work of absorption. 

 By means of all its roots the plant is anchored so that 

 its above-ground parts can grow up into the sunlight, 

 and not be upset by the first breeze that comes along. 

 By means of the tender tips of the roots and the hairs 

 which they bear (see Figure 3) the plant absorbs materials 

 which are to be used up there in the sunlight in the mak- 



