f 



BENCH-GRAFTING RESISTANT VINES. 223 



same angle. The length of the cut surface, in cuttings of 

 solid texture and full size, was about three times the 

 diameter of the cuttings, that is to say, the cut was made at 

 an angle of about 19. This maybe taken as the maximum 

 angle that can be used practically. For smaller cuttings 

 the length of the cut was relatively somewhat greater, beiug^ 

 about four times the diameter or about 14, which may be 

 taken as the minimum angle which should be adopted. The 

 tongues were made by a longitudinal cut, care being taken 

 not to split the wood, and usually commenced at about one- 

 third the distance from the sharp end of the cutting, and to 

 a depth about equal to the diameter. Thus when the two 

 cuttings were placed together the sharp end of one corre- 

 sponded exactly to the thick end of the other, so that no 

 portion of the cut surface was exposed, and the maximum 

 contact was obtained. The object of the grafter in making 

 his cuts is to make them as straight as possible, but it will 

 be found that a cut made by the most skilful hand is slightly 

 concave. This is, however, no objection, as this extremely 

 slight concavity is useful in allowing for the slight swelling 

 in the middle due to the insertion of the tongues. This is 

 probably one of the reasons why hand-grafting is generally 

 more successful than grafting with a machine, as a machine 

 makes a cut which is absolutely straight, and the ends have 

 thus a tendency to be drawn away from the cut surface of 

 the other cutting. The cut for the tongue is not made quite 

 parallel to the grain of the wood in order to minimize the 

 danger of splitting. 



Champin Graft. Perhaps the commonest method of 

 grafting used in California for small vines or cuttings is a 

 modification of the Champin method. The Champin graft 

 is made as shown in Fig. II. below. The modified method 

 is a compromise between the true Champin graft and the 

 English tongue graft. It is made in a way similar to that 

 described for the latter, but the tongue is made much deeper 

 and the end of the point (see Fig. 176, No. 12) projecting 

 over the cut of the opposite cutting is cut off. 



The Champin graft is based on the theoretical principle 

 that the greater the surface of contact between the two cut- 

 tings the greater the chances of union. Thus in the English 

 graft the amount of possible contact is theoretically only 

 about half that of the Champin. The latter is apparently 

 twice as great as the former, In practice, however, it is. 



