42 Plants and their Ways in South Africa 



cut off. To replace it two buds soon appeared. The tip, 

 which was placed in the ground, began to form the lacking 

 roots. This demand upon the plant retarded the growth of 

 the stem, which made no evident growth, while the branches 

 on the seedling increased nearly three inches. As a pine tree 

 grows older it loses the power of renewing lost parts. If the 

 tip meets with injury, a side branch will shoot upward rapidly 

 to take its place, leaving only a vacant space to tell the tale, 

 until the light and air cause the neighbouring branches to put 

 forth extra energy to close in the space. 



The Japanese have long been famous for their secret of 

 producing dwarf trees. Oaks over a hundred years old grow 

 comfortably in a small pot. Maybe if you bear this law in 

 mind you may discover their secret — or a new process. 



Cut back the roots and replant a thrifty acorn seedling. 

 When new shoots have formed repeat the operation several 



times. Have another seedling 



growing to compare the growth. 



According to this law, if one 



part of a plant grows to a large 



size it does so at the expense of 



other parts. The leaves on 



horizontal branches of Carissa 



ferox show this. They are 



arranged in pairs. The leaves 



which are exposed to the light 



are large, while the alternate 



pairs at right angles to these are 



not so well placed to receive the 



light, and for this reason, or 



because the pair on either side 



have developed at their expense, they remain much smaller. 



Other examples of the same nature may be seen in the study 



of flowers. 



Fig. 49. — Large and small leaves of 

 Carissa ferox. 



