100 Journal of Agriculture, Victoria. [10 Feb., 1917. 



Unless the sections of this layer are sufficiently close to one another 

 the new tissues will not unite, and the graft must fail. When a vine 

 cane is sevei'ed, and the cut ends are placed under suitable conditions of 

 temperature and moisture, nature heals the wound by causing the cam- 

 bium layer to throw out a cushion of healing tissue, or callus. In the 

 case of a graft, the cambium sections are so close to one another that 

 the masses of callus produced by stock and scion soon meet and press 

 strongly against one another. Exchange of cell contents takes place 

 between them by osmosis and shortly vessels and woody fibres make their 

 appearance; the cambiums of stock and scion each produce wood 

 internally and bark externally, with all the anatomical details peculiar 

 to each, and these new layers are continuous and intimately united ; in 



Fig. 13. — Photograph of a Section through a successful 

 a Year after Grafting. 



Yema ' ' Graft, 



The soft wood of the European {vinifera) scion is shown on the upper right- 

 hand half, whilst the denser wood of the resistant stock occupies the lower left- 

 hand half. The radial split, to the right of the photograph, occurred during 

 the drying of the specimen. 



other words, the graft has taken. As M. Vermorel concisely puts it§ 

 " a graft is a common cicatrization, or healing of two wounds placed in 

 contact." 



Fig. 13 shows the very thorough manner in which the new tissues 

 of stock and scion unite in a successful Yema gratt ; this is an actual 

 photograph of a section made through a Yema graft, at about the 

 middle of the scion bud, rather more than a year after the execution 

 of the graft. The woody part of the original bud (now dead) is the 

 black portion near the centre; around this is the new ring of woody 

 tissue, formed sines the knitting of stock and scion. A marked differ- 

 ence will be observed between tlie soft and rather spongy wood pro- 



§ '• Lo Greffage Pratique de La Vigne," by V. Vermorel. 



