PRUNING AND TRAINING. 25 



]i;itur;i!ly tends towards the summit of the stem; it 

 follows, therefore, that the lower branches become weak, 

 and soon die off, and the form that had been obtained 

 disappears, to be replaced by the natural disposition of 

 the tree ; that is, a naked stem carrying a head more 

 or less voluminous. It is, therefore, indispensable to 

 change the natural current of the sap, and thus main- 

 tain the direction towards each of the points to which 

 it is desired to train the branches. 



"We suppose an espalier (fig. 27) in which the 



Fig. 27. Espalier, in which the Circulation of the Sap is irregular. 



equilibrium of vegetation has been broken ; in order to 

 retard the vegetation in the direction in which the sap 

 flows too abundantly, and to favour those parts where 

 its flow is insufficient, we employ the following 

 means : 



Prune the strong branches, B, short ; but allow the 

 weaker ones. A, to grow long. We know that the 

 sap is drawn by the leaves ; therefore, in suppressing 

 upon the most vigorous parts the greater number of 



e 



