THE "PHILOSOPHY OF PRUNING. 269 



rent of the descending sap more abundantly into the 

 stem. It is hard to understand what is meant by 

 this explanation of the effects of pruning. Does 

 the sap descend down the stem till it arrives at the 

 weaker branches, and then ascend up them and in- 

 crease their size instead of that of the stem 1 If so, 

 the weaker branches would soon become the strong- 

 er ; or, rather, if trees have the property of sending 

 the s'ap from the strong branches to the weaker, all 

 the branches would be equally strong. The de- 

 scending sap, on reaching the weaker branches, 

 would become ascending sap. And if the small 

 branches be considered obstructions, preventing the 

 descent of the sap, the large branches must be 

 greater obstructions. But where does the sap de- 

 scend from ? Primers forget that they cannot cut 

 a live spray from a tree without lessening the quan- 

 tity of its leaves. Their theory is founded in error, 

 and all their reasoning is false." Bollard, in Farm, 

 Mag. 



This explains what often seems enigmatical to 

 superficial observers in vegetable economy, viz., 

 that moderate-sized trees from a nursery have or- 

 dinarily a much thriftier and healthier growth, and 

 arrive sooner to a good bearing state, when trans- 

 planted, than trees that are very large. In the for- 

 mer, the natural proportion between the roots and 

 the branches is preserved, the roots being taken up 

 nearly entire ; the sap-vessels, therefore, are filled, 

 and the growth is but partially retarded. While, in 

 taking up very large trees, whose roots have greatly 

 extended, the mouths of the plant are seriously di- 

 minished, the sap-vessels contract and become in- 

 durated in consequence of the diminished supply of 

 sap, and the tree must acquire new roots and new 

 sapwood by a slow process of growth ere it can 

 flourish with its accustomed vigour. The same evil 

 results from cutting off the entire top of a tree. It 

 is deprived of its elaborating organs ; and, although 



