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GRAFTING. 



This operation consists in inserting into the root, the stem, or 

 the branch, as the case may be, of a plant host, known as the stock, 

 a part of another plant, which is called the scion. It is performed 

 in a manner and under conditions such that they unite, and the 

 scion will derive from his host the stock the nourishment necessary 

 for its growth, and will bear fruit of the kind belonging to the plant 

 from which it was taken. On some idea of the circumstances 

 which make grafting practicable, and of the methods suitable to 

 the performance of this operation depend the success or the failure of 

 the graft. To be successful, grafting must be made with the right 

 kind of wood. The stock and the scion must be botaiiically related ; 

 the closer the relationship the more successful the graft. Grafting 

 is not practicable on all kinds of plants, but is restricted to those 

 botanically known as exogenous plants, which are possessed of pith, 

 wood, and bark, and grow outwardly. This term is used in contra- 

 distinction to that of endogenous, which refers to a class of plants 

 which increase by internal growth and elongation at the summit 

 instead of externally, and have no pith, wood, and bark. Reeds, 

 palms, and cereals belong to this order, and, for the reason referred 

 to, cannot be grafted. 



In order that grafting may be successful, the growing tissues of 

 both stock and scion must be closely fitted together, so that the 

 nourishing fluid may be forced by one into the other. For such an 

 interchange to take place the growing tissues of each must be fresh, 

 sound, and gorged with moving sap ; the tissues conveying such 

 sap must be in contact. These tissues are botanically known as 

 cambium, a word which means " exchange." It consists of a layer 

 of extremely delicate tissue formed between the wood and the bark. 

 The cells of this tissue have very thin walls, and they are filled 

 with protoplasma, or organisable nutrient matter. It shows like a 

 thin film of mucilage. These cells develop on the one side into 

 sap-wood or alburnum, which means " whitish," and on the other 

 side into new bark, whilst at the same time fresh cambium is formed 

 for the continuation of the work. 



It can thus be understood why endogenous plants such as 

 grasses, palms, etc., cannot be grafted. 



OBJECTS OF GRAFTING. 



This operation, which has been practised for ages without 

 number, possesses advantages which are often availed of by the 

 fruit grower. 



1. It enables us to cultivate, on roots foreign to the plant 

 itself, fruit trees which, on their own roots, would fail to thrive in 

 soils uncongenial. Thus the pear on the quince, the peach on the 

 plum or the almond, can be cultivated on a wider range of soils 

 than would be practicable were they growing on their own roots. 



