52 MANUAL OF AMERICAN GRAPE-GROWING 



Three methods of uniting stock and cion are illustrated in 

 Fig. 12. It suffices to grade by the eye into three lots large, 

 small and medium but some nurserymen prefer to secure 

 even greater accuracy by the use of any one of several mechan- 

 ical gauges. The methods of uniting stock and cion may be 

 described best by quoting Bioletti, from whom most of the 

 details already given have been summarized : 1 



Tongue grafting. 



"When the stocks and scions are prepared and graded the 

 grafter takes a box of stocks and a box of the corresponding 

 size of scions and unites them. Each is cut at the same angle 

 in such a way that when placed together the cut surface of 

 one exactly fits and covers the whole of the cut surface of the 

 other. The length of cut surface should be from three to four 

 times the diameter of the cutting, the shorter cut for the larger 

 sizes and the longer for the thinner. This will correspond 

 to an angle of from 14.5 to 19.5 degrees. The cut should be 

 made with a sliding movement of the knife. This will make 

 the cut more easily and more smoothly. 



"The cut should be made with a single quick motion of the 

 knife. If the first cut is not satisfactory, a completely new 

 one should be made. There should be no paring of the cut, as 

 this will make an irregular or wavy surface and prevent the 

 cuttings coming together closely in all parts. 



"The tongues are made with a slow, sliding motion of the 

 knife. They are commenced slightly above one-third of the 

 distance from the sharp end of the bevel and cut down until 

 the tongue is just a trifle more than one-third the length of 

 the cut surface. The tongue should be cut, not split. The 

 knife should not follow the grain of the wood, but should be 

 slanted in such a way that the tongue will be about one-half 

 as thick as it would be if made by splitting. Before withdraw- 

 1 Bioletti, Frederic T. Calif. Exp. Sta., Bui. 180: 108-112. 



