36 



PRINCIPLES AND PRACTICE OF PRUNING 



ology and common experience. I do not purpose to dis- 

 cuss mechanical injuries to the trees, as a result of wounds, 

 for we all know that such injuries are a result of careless 

 or injudicious pruning. My proposition is this: Does it 

 injure a plant to remove a part of it? Is the entire growth 

 necessary to a plant's health and longevity? 



39. The argument from philosophy. — There is an in- 

 tense struggle for existence among all organisms. The 

 world is now full, and there can probably be no perma- 

 nent increase in the sum total of animals and plants. If 

 one species increases, another must decrease. Changes 

 in the numbers of individuals are, therefore, largely mat- 

 ters of readjustment between different types. Each kind 

 is held down to a certain equilibrium in relation to other 

 kinds. It is easy to see that any species of animal or 

 plant could completely occupy the surface of the globe, 

 if it could multiply to the full extent of its powers. Not 

 only do some species compete with others, but the indi- 

 viduals of the same species compete with each other for 

 standing room, l^he greater the number of thistles in a 

 given field, the less is the opportunity for another thistle 

 plant to gain a foothold. 



Now, a tree is essentially a collection or colony of in- 

 dividual plants. Every branch, even every joint of the 

 branch, is endea\-oring to do what everjr other branch 

 does — to bear leaves, flowers and seeds. Every branch 

 competes with every other branch ; and there are more 

 germs of branches — that is, more buds — than there can 

 be branches upon any tree. So it comes that no two 

 branches of a tree are exactly alike, but are what their 

 position or condition makes them to be. .Some are strong 

 and some are weak. That is, there is no definite or proper 

 size or shape for any branch, as there is for the various 

 ])arts of an animal or a flower. The limbs and organs of 

 an animal are not competitors but co-partners, each per- 

 forming some function or office which another does not, 



