454 



Journal of the Department op Agriculture. 



irregular edges of the bark (plate 8, fig. A) at the upper and lower 

 edges of the wound should be cut back evenly, as shown in fig. B. 



" The scions which form the bridge should be selected from wood 

 of the previous season's growth. Either branches which grew the- 

 preceding season or water sprouts that are a year old may be used. 



"It is important that the scions should be a little longer than 

 the space that is to be bridged. This is in order that the middle 

 portion of the scions when put in position shall arch slightly over 

 the central part of the wound. This is illustrated in fig. D, where 

 a longitudinal section of a bridge graft is shown. 



" Before being placed in position, the scions are bevelled at each 

 end, both bevelled surfaces being on the same side of the scion, as- 

 shown in fig. C. This bevelling should be done with a long sloping* 

 cut, so that the wedge-shaped ends thus formed will be relatively 



Plate 3 



Details of bridge grafting. — 4, The trunk of a tree giHled by mice ; 

 i?, the wound cleansed and the bark along the margins trimmed back 

 to healthy, growing tissue ; C, a scion with bevelled ends ready for 

 insertion : B, longitudinal section of the tiunk with scions in place, 

 showing their insertion under the bark of the trunk {w) ; E, scions in 

 place ready for waxing. 



thin, to permit their being thrust well under the bark without danger 

 of separating it unduly from the cambium at the point of insertion. 

 Eeference to fig. D illustrates this feature. The placing of the scions 

 in position is facilitated if the bark at the margins of the wound is 

 slit for a short distance at the points where the ends are to bo inserted 

 (fig. C). 



" The number of scions required for a bridge graft will depend 

 largely upon the size of the trunk. No fixed rule can be given. The 

 larger the number,- the more complete will be the restoration of the 

 connection between the parts above and below the wound ; V)ut, if 

 placed too close together, the bark at the margins of tlie wound 

 between the scions will be raised. The starting of the bark, except 

 at the immediate points of insertion of the scions, must be avoided. 



