WHY PLANTS GROW 13 



will crops grow in ground covered with water, because 

 all growing plants must have air, and much water 

 keeps the air out of the soil. There is still another 

 requisite to plant growth, and that is light. No plant 

 grows well in dense shade 1 , and without sunlight plants 

 always have a yellow and sickly appearance. 



Summary. Good seeds and proper conditions of 

 soil, moisture, air, heat and light are essential to plant 

 growth, and a part of the study of agriculture consists 

 in determining just how to. control these conditions. 

 "What ?" you ask, "Can the farmer control the amount 

 of heat, air and moisture in the soil?" He can, and 

 it is the purpose of this little book to teach the farmer's 

 children how it may be done. 



A good bulletin on the subject treated in this chapter may be 

 had free on application to the Secretary of Agriculture, Wash- 

 ington, D. C., or to your Senator or Representative in Congress. 



Write for Farmers' Bulletin, No. HI. The Farmer's Interest 

 in Good Seed. 



Experimental Study of Seeds. 



1. Place a folded newspaper in the bottom of a 

 cigar box, a crayon box, or on a plate; moisten with 

 water, and place another folded newspaper over the 

 first one. Between the papers place one hundred of 

 the seeds to be tested, and set aside in a warm place 

 for a few days. Keep the paper moist but not wet. 

 At the end of a week the number of sprouted seeds 

 represents the percentage of good seeds. 



2. Select ten very small seeds and an equal num- 

 ber of very large seeds of the same kind, and plant 



