THE BOOT 25 



into a cold subsoil. Also, the surface soil is richer in 

 plant food, and so the roots run sideways as well as 

 downwards. 



3. How roots and branches correspond. Can 

 you tell me now why the feeding roots of a tree are 

 most numerous at the points where the rain runs off 

 the leaves ? In a shower, you sometimes stand under 

 a tree as you would stand under a great umbrella. 

 Watch where the rain drops as it runs off the leaves. 

 If you dig at these points, you will find that the tree 

 has placed feeding roots just where the rain drops. 

 But there is no hard and fast rule ; for the roots go on 

 farther if there be good moist soil beyond. Often a 

 root will run out in this way until it is longer than 

 the highest point of the tree. 



4. How sodden ground hurts the root. The 

 root must have moisture, but too much moisture is 

 almost as dangerous as too little. When there is too 

 much moisture the root cannot get air. An exploring 

 root will avoid a sodden patch just as it will avoid a 

 stone. A simple experiment will show the damage 

 done to a plant by earth that is too wet. Place side 

 by side in the open air, where they can get the rain, 

 a well-drained pot of wheat seedlings and a jam-tin 

 pot of wheat seedlings ; both sown at the same time. 

 Give exactly the same amount of water to each pot. 

 The earthenware pot is porous to air, and any surplus 

 water passes out at the side or through the hole in the 

 hottom. The jam-tin cannot receive air through its 

 sides, nor can it get rid of water when there is too 

 much. Compare the growth of the seedlings in the pot 

 and in the tin. When the wheat is about eight inches 

 out of the ground, take the plants up carefully and 



