THE MUTUAL INFLUENCE OF THE STOCK 



AND GRAFT. 



BY A. A. CKOZIER. 



The question of the influence of the stock upon the graft, and vice versa, 

 is one of those subjects in plant physiology which has never been system- 

 atically studied by the botanist or horticulturist, and upon which widely 

 differing opinions are held. The German botanist, Gartner has col- 

 lected the largest amount of evidence on the subject; several French 

 botanists have experimented and written upon it, and a prize for the best 

 memoir upon the subject has been offered by a Belgian horticultural 

 society. English gardeners have recorded numerous observations in the 

 English horticultural press. In our own country it may be mentioned 

 that Dr. E. L. Sturtevant and others have brought together considerable 

 information in the Transactions of the Massachusetts Horticultural 

 Society, Prof. L. H. Bailey has presented a brief analysis in Garden and 

 Forest, and an essay upon the subject has appeared in a recent bulletin of 

 the U. S. Department of Agriculture. 



In the following pages I have brought together most of the published 

 material on this subject ia such a way as to show the various opinions 

 which have been held, and the evidence on which they are founded, 

 Writers upon grafting have usually treated separately the influence of the 

 stock upon the graft and the reflex influence of the graft upon the stock. 

 I have found it more convenient to take up and discuss each kind of mod- 

 ification by itself, whether appearing in the stock, in the graft, or in both. 



OPINIONS ON THE SUBJECT. 



Erasmus Darwin recorded, in A. D. 1800, a number of cases of apparent 

 influence of the stock and scion upon each other, but said: 1 "It is not yet 

 certainly known whether the ingrafted scion gives or takes any property 

 to or from the tree which receives it, except that it acquires nourishment 

 from it." 



Thomas Andrew Knight, who probably made more experiments and 

 observations in grafting than any other man has made, recorded a few 

 instances where the stock affected the character of the fruit, but believed 

 that such modifications were generally due merely to an obstruction of the 

 sap as the result of the grafting, the resulting changes in the fruit being 



i Phytologia, p. 886. 



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