Pruning Fruit Trees. 165 



plant, from the minutest fibre to the ponderous stem, has its 

 own useful office to perform ; but as the development of all 

 those parts entirely depends on the leaves, it is on that ac- 

 count I consider them the principle organs of the vegetable 

 fabric. The roots absorb moisture (containing the food of 

 plants,) by their extremities, and it is transmited from them 

 through the stem by means of channels formed by nature 

 for that purpose, to the leaves, where it undergoes a chem- 

 ical process. The fluid on entering contains many different 

 substances, owing to the particles of matter it meets with 

 in its progress through the vessels of the alburnam ; this 

 fluid does not become the proper food until it is duly ex- 

 posed to the sun's rays, which acts on the cuticle of the 

 leaves, when what fluid that is superfluous passes ofl' by 

 evaporation, and that which is left becomes elaborated and 

 prepared as the proper food, passing into tlie system and 

 depositing a new layer of wood to the outside of exoge- 

 nous, and to the inside of endogenous, structures, passing 

 on to the roots, always leaving something after it that adds 

 to the diameter of each part it passes through, and finally 

 elongates the tips of the roots or forms new ones. The 

 matter that does all this is prepaied by the leaves, by which 

 alone the great importance of them is clearly shown. It 

 is an admitted fact that the greater the quantity of leaves 

 over a given part, the more that part increases in diameter. 

 The secretions for fruit are likewise prepared by the leaves, 

 and deposited in the tissue for the ensuing year's fruit; 

 hence the more leaves the more secretions for fruit will be 

 formed; but this does not hold good in all cases; for in- 

 stance, strong rank leaves that hold or receive no proper 

 juices and leaves not fully exposed to the sun's rays are of 

 no use for the formation of secretions ; therefore, if the leaves 

 are not properly exposed to the sun's rays digestion is pre- 

 vented and they become worse than useless. It is highly 

 essential that the juices are prevented from being lost in the 

 formation of useless wood. 



The system I am going to describe, which is prac- 

 tised in the London Horticultural Society's garden, and 

 first put into practice in England by Mr. R. Thompson, the 

 acknowledged leading pomologist of Europe, principally 

 depends on summer management ; it is as follows : — 



Allow the young shoots to grow until the leaves become 

 too crowded ; then cut off" their growing points only ; by 



