40 FIRST STUDIES IN PLANT LIFE 



sometimes called pith-rays. The pith is a storehouse 

 of food for young shoots. It is very active in a 

 one-year old plant ; but, as the plant becomes older, 

 the pith becomes smaller and less active, and finally 

 dies and disappears. 



Questions and exercises : — 



(1) A hide-bound tree is one in which growth is checked by 

 unhealthy bark that cannot expand. Explain. 



(2) Can you see from the last question why it is important to 

 grow trees so that the stems and branches are not bare to the 

 sun? 



(3) Explain how ringing kills a tree. 



Composition exercise : — Tell the story of how a tree was 

 able at last to hold up thousands of leaves. 



Drawing exercise : — Draw the cut stem of a tree that has 

 leaves with a network of veins. Show the rings of annual growth. 



Note. —Two- or three-year old wood from a Ndgoroua plum tree 

 shows the rings well. 



VII.— THE STEM.— Pakt II. 



1. Root-sap tubes and leaf-sap tubes. — We have 

 seen that there are two kinds of sap-tubes, one kind 

 running up from the root, and the other kind running 

 down from the leaves. Perhaps you have heard of 

 the wizard who could see the two streams of sap 

 running side by side — one up and the other down ! 

 What wonders we could see inside a tree if we had 

 eyes like his ! And what sounds we could hear if 

 only our ears were quicker ! With quicker ears, the 

 October woods would be filled with the noise of the 

 rush of the spring-sap, sounding like the noise of 

 many waters. It would be deafening ; and it is well 

 for us that our ears are dull ! 



