GRAFTING AND HYBRIDIZATION. 295 



often prefer to ennoble, as they say, a fruit by grafting it upon 

 another of excellent quality. Experiments of this kind have 

 not yielded decided and convincing results, though the custom 

 at present is to employ vigorous seedlings as stocks without 

 regard to their origin. 



The influence of the scion upon the stock is more probable 

 theoretically than that of the stock upon the scion, since the 

 elaboration of sap occurs in the leaves, from which it must be 

 distributed downward. Recent experiments with the variegated 

 abutilon have demonstrated that the foliage of the stock 

 becomes variegated while the scion is growing upon it, and 

 when the latter is removed from the plant, the variegation of 

 the foliage disappears. Nevertheless, it is hardly to be expected 

 that any important results will be attained in this direction, in 

 respect to the modification of flowers and fruits, though experi- 

 ments are desirable. It is well known that some varieties have a 

 remarkable inclination to sport, producing differently colored 

 flowers upon different branches. This may result from a mix- 

 ing of qualities by hybridization, or possibly grafting, upon the 

 supposition that a portion of a cell of the scion has united with 

 a portion of a cell of the stock to form a sort of mechanically 

 crossed cell, which has reproduced itself with infinite variations. 

 But neither hypothesis accounts for the well-known fact that 

 this tendency to sport is very rare in comparison with the whole 

 number of hybrid and grafted plants. 



Tomatoes, potatoes, cucumbers and even grasses have been 

 successfully grafted, but the process is generally confined to 

 hard-wooded plants with exogenous stems. Soft-stemmed and 

 endogenous plants are usually grown from cuttings, which, in a 

 moist atmosphere with bottom-heat, root without difficulty. In 

 this way tens of thousands of potato plants have been started 

 during the past few years. 



Many wild plants, especially among the lower orders of the 

 vegetable kingdom, are reproduced by buds which either develop 

 in connection with the parent plant, or separate from it and 

 establish themselves in the soil. Occasionally buds assume the 

 form of bulblets in the axils of leaves, as in the tiger-lily, or on 

 the flower-stalk, as in the top-onion. These fall to the ground, 

 sometimes before and sometimes after sprouting, and thus 

 reproduce their kind. Among the numerous methods in which 



