80 ON THE PRUNING OF VINES. 



rives, and by that time the sap being in full motion, 

 all is life, vigour, and activity, from one extremity of 

 the vine to the other. 



The leaves attract the sap as soon as it reaches their 

 vicinity, and by one of the most wonderful processes 

 that can be conceived, the result of exquisite organisa- 

 tion, elaborate and prepare it, and render it fit for the 

 nourishment of all the parts of the plant. The sap, after 

 being thus prepared, is called the proper juice of the 

 plant. It then returns downwards betwixt the bark 

 and the alburnum, and in its descent is distributed lat- 

 erally to every part of the plant, until it finally reaches 

 the extremities of the roots. During its descent, a 

 considerable portion of it is expended in the formation 

 of a concentric layer of woody substance betwixt the 

 bark and the wood, on every branch, and also on the 

 stem, which layer becomes the new alburnum. 



Now, it is of importance to remember, that every 

 branch annually requires this new concentric layer ; 

 that this layer is formed from the proper juice prepared 

 in the leaves ; and that the thickness or thinness of 

 this layer depends on the proportion which the quantity 

 of proper juice, so prepared, bears to the number, length, 

 and size of the branches, which it has in its descent to 

 cover and feed. 



If, therefore, the foliage of a vine be strong and vig- 

 orous in its growth, and there be no naked branches be- 

 twixt the stem and the shoots which produce the foli- 

 age, then the proper juice in its descent will deposit 

 on the stem a thick layer, and will also descend into 

 the roots in great quantity. But if there be a great 

 number of naked branches which the proper juice in its 

 descent has to clothe and nourish, then, having to spread 

 itself over a much greater surface, the new layer will 

 be comparatively a thin one, and the surplus left to en- 

 ter the roots, proportionately lessened in quantity. And, 



