THE GREEN-HOUSE. 



147 



and the upper parts of almost all plants are those 

 where blossoms are first produced. 



Where woody plants so treated are yet tardy of 

 producing flowers, this tendency may be promoted by 

 cutting off a ring of bark from the stem ; or from any 

 one of the branches of the plant, if the effect is 

 meant to be limited to a branch. The season for 

 performing this operation is when the plant is in a 

 growing state in spring : the ring or circle of bark 

 should not exceed a fourth of an inch in width, in 

 order that it may heal up at the end of the same season, 

 or in the course of the next year. In green-house 

 plants, the best part of the stem on which to perform 

 the operation, is immediately under the surface of the 

 soil, by which means the notch is unseen. The ring 

 should penetrate to the wood, but no deeper. 



The rationale of the operation of ringing is as fol- 

 lows : — The sap of plants, when they begin to grow 

 in spring, rises from the roots to the upper extremi- 

 ties of the shoots through the vessels of the wood, 

 and chiefly of the young wood : it is elaborated or 

 prepared by the leaves, it is supposed, as the blood of 

 man is by his lungs and liver, and then it is returned 

 by the bark, nourishing each part as it goes along, and 

 carrying down a large supply of nourishment to de- 

 posit in the root for next season. Now the ring, it is 

 further supposed, intercepts the supply of nourishment 

 on its way to the root, and obliges it to be deposited 

 in the buds of the branches ; thus giving a great acces- 

 sion of force to them, and causing some or many of them 



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