INFLUENCE OF CION AND STOCK. 247 



large fruit and the other small. The number of speci- 

 mens upon each tree being reduced to an equal number, 

 the difference in size remained the same. With such ex- 

 amples before us, we cannot but conclude that the stock, 

 in some instances, does exert sufficient influence to change 

 the size of the fruit, as well as the form of the tree. 



Sixth, The stock will not only impart vigor to the graft, 

 but also transmit diseases. It is therefore just as import- 

 ant to avoid the one as to endeavor to secure the other. 



INFLUENCE OF THE CION ON THE STOCK. The influ- 

 ence of the cion on the stock is a subject only occasionally 

 referred to in our modern horticultural works. Down- 

 ing says: " The influence of the graft on the stock seems 

 scarcely to extend beyond the power of communicating 

 disease." But, if we have discovered this much, it proves 

 that there is an influence, and if it is sufficiently potent 

 to "communicate disease," then it is probably powerful 

 enough to impart other properties as well. Mr. J. J. 

 Thomas, in his " American Fruit Culturist," edition of 

 1849, says: "The extension of the stock by successive 

 depositions from the leaves of the graft and through the 

 cellular system of the bark, so as to preserve the strict 

 specific identity of the wood of the former, is familiar to 

 every practical cultivator." The same seedling Cherry 

 stocks, grafted with sorts of different degrees of vigor, 

 soon vary in amount and size of the fibrous roots. Trees 

 of the Imperial Gage and Jefferson Plums, a few feet in 

 height, when budded on the Wild Plum, were found to 

 have only half the amount of roots possessed by the un- 

 budded stock of the same age. 



Every nurseryman must have observed that some 

 varieties of the Pear, as well as of the Plum and Cherry, 

 have a far greater number of fibrous roots than others. 

 So marked is this difference that the common laborers in 

 the nursery soon learn to distinguish them and will pro- 

 ceed quite differently in digging the trees of each variety, 



