THE SUGAR PRUNE 157 



scent to which Professor Johannsen has given 

 special attention. 



But it must be understood that it is exceedingly 

 difficult to carry the experiment in the case of 

 the prune to the stage at which the type becomes 

 absolutely fixed, for the reason that there are so 

 many other qualities to be considered. 



This matter of varying qualities represented 

 in the same seed we have discussed before, and we 

 shall have occasion to refer to it again and again. 

 Here it suffices to note that the case of the prune 

 is akin to others that we have examined, for 

 example the hybrid walnuts and the early cher- 

 ries, in that the qualities for which we have bred 

 are so numerous and so varied that they can 

 be aggregated only in one seedling among 

 many thousands, and could not be fixed with- 

 out a long series of generations of additional 

 breeding. 



Fortunately this is of no practical consequence 

 because the prune, like other orchard fruits, may 

 best be propagated by grafting. From a single 

 seedling we may thus develop, in a short time, an 

 entire orchard or a series of orchards. 



Such is in practice the method of propagating 

 the sugar prune. It is obvious that plants thus 

 grown partake of the very substance of the 

 original seedling; they are part and parcel of it, 



