106 UNIVERSITY OF CALIFORNIA EXPERIMENT STATION. 



size. Or, looking at it another way, the smallest cutting in any grade 

 is just five sixths of the diameter of the largest cutting of the same 

 grade. 



The green bark or growing layer on small cuttings is thinner than that 

 on large cuttings, but in all it is just about one sixth of the diameter of 

 the whole. If, therefore, the smallest scion of any grade is grafted on 

 the largest stock of the same grade the outer edge of the bark of the 

 scion will be in contact with the inner edge of the bark of the stock. 

 This brings the growing layers sufficiently near to insure the formation 

 of a good union. This, moreover, is an extreme case ; the great majority 

 of the grafts will fit much more nearly than this. 



Comparing these results with those obtained with the notch grader it 

 will be seen that the cuttings between % i ncn an d % inch are sorted 

 into only four sizes with the slot, while the notches make five sizes 

 of the same cuttings. This reduction of the number of sizes is of some 

 practical advantage, especially as there is no loss of accuracy, but 

 rather a gain, as the smallest sizes vary only as 5 : 6, while those of the 

 notch grader vary as 4 : 5. 



A practised workman will grade almost as quickly with a notch 

 grader as with the slot, but in the hands of a beginner the latter is 

 much more rapid and accurate. 



Four grades is the least number that should be made of cuttings 

 between % inch and ^2 inch. With this number some of the cuttings 

 will not fit exactly enough to satisfy some grafters, and a little eye 

 sorting may have to be done while grafting. This sorting by the 

 grafter consumes a great deal of valuable time, and it is better to use 

 a more closely graduated scale if the first does not give satisfaction. 

 The third scale is sufficiently close to satisfy the most particular. 



In using the grader, every cutting should be measured through its 

 longest diameter or much of the accuracy of the sorting will be lost. 

 The flattening is always on the side toward which the bud points, so 

 that the longest diameter is that at right angles to the one passing 

 through the bud. In using the slot grader, therefore, the cutting 

 should always be held with the bud pointing horizontally. 



Advantage may be taken of the difference in the two diameters to 

 compensate for the variation in size of cuttings in the same grade. As 

 the cuttings vary as 5 : 6 and the two diameters vary in about the same 

 ratio, the smallest scion cut on the flat side will fit accurately the 

 largest stock cut on the narrow side. The only consequence is a slight 

 angle at the point of union, as shown in Fig. 7, D 1 and 3. 



Methods of Uniting Stock and Scion. Innumerable methods of 

 cutting and splitting the stocks and scions have been described and 

 recommended. "We will have little difficulty in choosing the best of 



