142 THE PHYSIOLOGY OF PLANTS 



from the normal condition. The wood cylinder is only slightly 

 developed, bat the cortex and pith are excessively enlarged, 

 the cortex of the stem being often continuous with the massive 

 cortex of the fruit-stalk. This form of branch is very sensitive 

 to frosts. If it becomes necessary, in the case of such trees, to 

 produce some long shoots, it is advisable to prune away the 

 deformed spurs to their base, and to stimulate the dormant 

 buds to farther development. 



In the case of cherries, to prevent long sterile branches, it is 

 necessary to constantly renew the production of long shoots. 

 This can be done by pruning back the shoot which has just 

 borne fruit to about four basal buds. Two of these will in 

 general grow out next year, and the stronger of the two will 

 be retained as the fruiting branch. The same process will be 

 repeated with this branch. 



The effect of pruning, therefore, is to stimulate a number of 

 buds to grow out which would otherwise have remained dor- 

 mant. The uppermost buds of each shoot are the most ready 

 to develop and produce the strongest lateral shoots; towards 

 the base of the shoot the buds become more and more difficult 

 to stimulate. 



§ 29. How may pruning be used to regulate the natural 

 development of the tree ? 



Among the large number of varieties of our fruit-trees and 

 decorative plants, there are many in which the branches are 

 not produced in a way that satisfies our wishes. Thus there 

 exist varieties in which the branches are always bent, others 

 in which the woody shoots are short and few in number, but 

 which very readily produce flowering buds ; others, on the 

 contrary, are inclined to run to wood, but only produce few 

 fruit-buds. 



Similar tendencies may be produced by unfavourable situa- 

 tions. Pruning should in such cases be used to overcome such 

 defects. All our efforts then will be in the direction either 

 of producing more leafy shoots or in promoting the formation 

 of fruiting buds. In the first case we prune fop wood, in the 

 latter case we prune for fruit. 



