PROPAGATION BY GRAFTING AND BUDDING. 65 



nearly all woody or cellular (herbaceous) exogenous stems. In 

 the case of young seedling stocks, where the size varies from 

 one-eighth to half an inch in diameter, one, or at most two 

 scions are sufficient ; but in the case of old stems of Apple, 

 Pear, and other fruit-trees which are to be renovated by graft- 

 ing, half-a-dozen or more cleft grafts may be inserted so as to 

 increase the chances of success, it being easy to thin out some 

 of them with the knife if more grow than are required. The best 

 season for grafting hardy trees is undoubtedly in the spring, 

 when the sap is in motion ; but by growing the stocks in pots, 

 and taking advantage of artificial heat and moisture, the opera- 

 tion may be performed nearly all the year round. Azaleas, 

 Camellias, Allamandas, Francisceas, and many other stove and 

 greenhouse plants, and even hardy shrubs, as Conifers and 

 Roses, are often more successfully operated on under glass. 

 The genial heat and humidity of a propagating house or case 

 greatly facilitates the union of scion with stock, by quickening 

 vegetation, and inducing the junction of the generative cambium 

 layer, by which alone the union can take place; and the 

 operator should always bear in mind this fact, and aim at 

 quickness and neatness in applying the inner layer of bark 

 and the cambium layer exactly one upon the other. The 

 blade of the grafting -knife should be as smooth and as 

 keen as possible, so as not to bruise or mutilate the tissues ; 

 and both graft and stock, if small, should be prepared by the 

 smallest possible number of clean and decided cuts. Quick- 

 ness is requisite to prevent the delicate tissues from drying 

 during the operation; and after the scion is accurately fitted in 

 its place, care must be taken not to shift it in any way when 

 tying or binding. 



Embryonic grafting or inarching is not unfrequent in nature, 

 although apparently accidental, and is the result of young 

 tissues being pressed firmly together when in a pliant and 

 plastic state. In 1870, Mr T. Meehan observed that about 

 two per cent of young Osage Orange plants (Madura 

 aurantiaca) were united twins, and the pairs of young stems 

 thus joined appeared to have sprung from the same seed, and 

 not being separated by any intervening tissues, they had fused 

 themselves together. In alluding to this subject (see ' Gar- 

 deners' Chronicle', 1871, p. 104, 199), the editor observes that 

 the fact of two embryos being in the same seed is intelligible 

 enough, seeing that several germinal vesicles are developed in 

 the same sac, and it is possible for more than one of these 

 to become fertilised, although the reverse of that is generally 

 the case. Duplicate germs or embryos are common in the 



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