ON THE TRAINING OF VINES. 



81 



CHAPTER X. 



ON THE TRAINING OF VINES. 



To train a vine on the snrface of a wall, is to regu- 

 late the position of its branches, the principal objects 

 of which are, to protect them from the influence of the 

 wind ; to bring them into close contact with the wall, 

 for the purpose of receiving the benefit of its warmth; 

 to spread them at proper distances from each other, 

 that the foliage and fruit may receive the full effect of 

 the sun's rays ; and to retard the motion of the sap, 

 for the purposeof inducing the formation of fruit-buds. 



The flow of sap, it must be remembered, is always 

 strongest in a vertical direction, and weakest in a 

 Fio-. 1. 



downward one; thus 

 direction of a, fig. 1. 

 greatest degree of force 

 the roots can propel it 



if a shoot be trained in the 



the sap will ascend with the 



with which the strength of 



if it be trained in the direc- 



tion of 6, c, or d, that force will be gradually dimin- 

 ished, as the shoot approaches the horizontal position 

 of d : nevertheless, the difference in the flow of the 

 sap betwixt the shoot at «, and that at d, will not be 



