EVIL EFFECTS OF PRUNING. 253 



lying in readiness to embrace any favoured opportunity 

 of appropriating the materials necessary to form active 

 buds and shoots ; and when any neighbouring sap- 

 vessel is ruptured, or the sap diverted from its natural 

 course, it so far affects those latent buds as to arouse 

 them into life and action, and ultimately to form buds, 

 branches, and leaves. So easily are these latent buds 

 influenced, that even a slight variation of temperature 

 will do it. It is upon this known principle that thin- 

 ning is practised, and according to which all pruning 

 should be regulated. 



The fine, healthy, and vigorous spray that thus 

 covers the dismembered parts and newly pruned trees 

 during the first summer after the operation has taken 

 place, is very apt to betray those of limited experience, 

 and lead them into fatal errors. The spray thus pro- 

 duced being well nourished and abundantly supplied 

 with sap, is so far accelerated in growth as to prolong 

 its growth in autumn till suddenly stopped by frost, 

 while the wood is yet tender and immature ; and conse- 

 quently a large portion of it withers and decays, and 

 what of it remains still vital is so much weakened and 

 otherwise injured, that the leaves which next season 

 cover it are weakly, ill-formed, small, spotted, and 

 blemished, and scarcely one of them free from disease. 



The injurious effects of this form of pruning are 

 not so obvious in conifers as in hardwoods, and are 

 most conspicuous in the oak, wych-elm, and Spanish 

 chestnut. 



Ten years ago the writer pruned a considerable 

 number of Scots pine trees in different ways and to 

 different degrees, from that of removing only the ter- 

 minal shoots of the lateral branches, to that of denud- 

 ing them of all except as many small twigs upon each 



