INFLUENCE OF THE SOIL AND STOCK. 29 



zenburgh, or a Bellflower, preserve their identity 

 upon them all. 



Salt peaches or plums, show that foreign sub- 

 stances may enter the juices, and modify or change 

 the quality of the fruit, as well as poison or induce 

 disease in the tree. Soluble substances in the soil 

 may thus exert a sensible influence. In the same 

 way, the peculiar character of the sap and secre- 

 tions of a stock may produce a like result. 



Stocks may hasten or retard ripening ; they may 

 affect the size, color, and quality of fruit. The 

 temperature, depth, and other characters of soils 

 may do the same. Tender kinds are made hardier 

 on hardy stocks, not because of any specific influ- 

 ence, but the usual supplies of sap are withheld 

 earlier in autumn, and the tender wood has more 

 time to mature precisely similar to the planting 

 of tender trees on sterile or rocky soils, which cause 

 an earlier cessation of growth.* 



No other influence than these can be produced 

 by the stock upon the graft. Lord Bacon correctly 

 remarked " that the scion overruleth the stock quite, 

 the stock being passive only." The change which 

 takes place when the sap is converted into the pro- 

 per juices, and thence into fruit, is effected entirely 

 by the leaves ; hence when a pear is grafted on a 



* It would be interesting to inquire why the Maydukc 

 Cherry should frequently have ripe fruit on one branch of the 

 tree, and green fruit on another; and why other trees occa- 

 sionally present similar variations. 



