42 



THE GARDENER. 



perfectly formed rudiments of one. Hence the portion 

 intended to be propagated must contain a bud or 

 buds. The diametrical increase of exogenous plants 

 proceeds outwardly, in consequence of the formation 

 of new layers of alburnum, interwoven into the pecu- 

 liar texture of the tree by extensions of the medullary 

 rays. The alburnum is interposed between the inner 

 bark and the heartwood, with both of w^hich it is in 

 vital or organized union. The greater part of the 

 heartwood of a tree may be bored out, and, though 

 made a hollow cylinder, it will still continue to increase. 

 The outer bark may be removed, and a new one will 

 gradually be formed ; but, if the alburnum be entirely 

 destroyed, death will be the consequence. 



It appears therefore that buds wdth some portion of 

 alburnum are the parts essentially necessary for propa- 

 gation ; for although the heartwood and bark be or- 

 ganized, yet they are but passively so, and have not 

 the power of extending organization to new matter 

 when they are deprived of the media of buds and al- 

 burnum. Keeping therefore the im^portance of the 

 latter in view, the best mode of operation is that 

 whereby the greatest possible extent of the alburnum 

 of the stock and graft is brought into exact contact, 

 without making too extensive a wound. If the sec- 

 tions of alburnum can be made to coincide in every 

 point, the result of the operation will be the most per- 

 fect that can be obtained. 



The modes of grafting most generally practised 

 are, v/hip, cleft, saddle, and crown grafting. Of these 

 wMp -grafting is by far the commonest, and is per- 

 formed as follows : — The stock is cut over, sloping, 

 above a smooth and straight part. The end of the 

 scion is cut sloping and thin towards the lower end. 

 Then on the same side of the stock as that of the low- 

 est part of the slope made in cutting off its top, a slice 

 is cut clean off, in length equal to that of the cut part 



