376 



LIFE ON THE EARTH 



pith, while in the second it rose through the woody tissue 

 within the bark. 



Experiment 117. Examine a cross section of a hardwood tree 

 several years old, -and if possible of a palm. Notice the ringlike 

 arrangement of the layers in one and the absence of all such arrange- 

 ment in the other. 



In Experiment 117, when the cross section of a dicoty- 

 ledonous tree was examined, it was found to be composed 

 of circular rings, but no such rings are found in the cross 



A SPLENDID TREE DEVELOPED UNDER IDEAL CONDITIONS 



section of the monocotyledonous tree. When later we 

 examine the seeds of beans and corn, we shall find that 

 they also differ very much. 



When the bark is removed from a stem, like the willow 

 or apple, the soft, smooth layer underneath is found to be 



