8 PLANT LIFE 



in such a way as to avoid shading each other too much. Thus the 

 plant secures all the light possible. Trees in dense woods grow 

 tall in search of light. There is little need for them to produce 

 side branches, because the sun would not reach them. 



If rows of corn or garden crops are planted east and west each 

 plant will receive more light during the young growing stage than 

 otherwise. Of course if the distance between plants in the rows 

 is the same as the distance between rows the direction will make 

 no difference. 



THE ROOTS 



Young plants soon after germination produce rootlets at the 

 lower end of the hypocotyl. 



Purpose of Roots. Besides holding the plant in place, the 

 roots gather moisture and plant food from the soil. Indeed all or 

 nearly all of the moisture taken in by plants must enter through 

 the roots. The food gathered by the roots must be dissolved in 

 the water of the soil. 



The amount of water required by growing plants is difficult to 

 comprehend. Many of our field crops may require 500 times as 

 much water as dry matter during their growth. Thus a ton of 

 mature dry corn fodder may have required 500 tons of water from 

 the soil where it grew. If this amount of corn is grown to maturity 

 in 125 days, then four tons of the soil water would be the average 

 amount taken in by the ton of corn each day. It is for this reason 

 that much attention must be given to the matter of soil moisture 

 for our growing crops. 



How Water is Acquired by Plants. When the water in the 

 soil is distributed in films through the grains, the roots of the plant 

 must be finely divided and come in close contact with these films 

 to obtain the water. The fibrous roots of half-grown plants in 

 the garden may reach from one row to the next. Some are at 

 considerable depth, and others near the surface. 



Root-hairs. For the purpose of greater increase in the sur- 

 face of fibrous roots, numerous root-hairs are produced on the 

 surface, particularly on the younger growth, but not at the 

 growing tip. When the root-hairs are examined closely they give 

 the appearance of fine white plush, as each is very short and the 

 mass is dense and soft. The walls of this fine growth are very 

 thin and water can be taken in readily. A study of root-hairs 

 can easily be made by germinating pumpkin or other large seeds 

 on moist cloth, and allowing the growth to continue for a few days. 



