Daniel's experiments anu conclusions 



173 



FIG. 147— BUNDLES OF 

 ClONS FOR SHIPMENT 



spring of the grafted plant than in the plant itself. Graft- 

 ing, as a means of retaining variations acquired under 

 culture, is useful only in the case of trees, and difference 

 between seedling fruit trees and varieties producing them 

 (199) may be explained in part by the effect of grafting 

 on the progeny of the grafted plants. 



Grafting which produces a var- 

 iation in the seed may be used 

 to produce new varieties. Since 

 this variation can frequently be 

 directed in a given way, it is pos- 

 sible almost to a certainty by re- 

 peated grafting to impart definite 

 characteristics of flavor, form, color, etc., to plants which 

 vary readily under culture. In other cases grafting may 

 produce variations which, though hard to obtain, after 

 once appearing, may be directed definitely. 



221. Asexual hybridization — Formerly it was believed that 

 grafted cions lost none of their own characteristics and acquired 

 no new ones from the stocks on which they were grafted, but the 

 experiments of Daniel and other investigators indicate that these 

 views must be modified. For Daniel has proved that hybrids pro- 

 duced by grafting can be fixed and propagated true to kind, but he 

 draws the conclusion that ase.xual hybridization is neither con- 

 stant, regular nor very frequent. In its results it is somewhat 

 similar to cross pollination, but has a wider application, and the 

 resulting forms are less constant in character. 



Grafting is not always a certain means of perpetuating variations, 

 although it generally is. In itself it may occasion variation, which 

 in turn may be fixed by grafting. In order to produce a given 

 variation by grafting or to add to a plant a character it lacks, 

 it is necessary to graft it on another plant which is superior to it 

 in the quahty sought. In grafting hybrid vines to secure a desired 

 character, it is necessary to graft together two vines having 

 common blood in such proportions that the sum of the blood of 

 the characters desired shall be greater than the blood of any other 

 strain in the graft. Modification in vines as regards eradication 

 of the foxy flavor, increase in size of berry, resistance to exterior 

 agents, etc., can thus be obtained. 



The problem of the French grape industry, Daniel declares, is 

 to unite American root resistance (to phylloxera) to the French 

 quality fruit. He says this will probably be done, not by sexual 

 hybridization alone, but by rational combination with asexual hy- 



