234 Plant-Breeding 



of producing new varieties, each parent to the proposed 

 cross should be chosen in agreement with the rules already 

 specified, and also because it possesses in an emphatic 

 degree one or more of the qualities which it is desired to 

 combine; and the more uniformly and persistently the 

 parent presents a given character, the greater is the chance 

 that it will transmit that character. It has already been 

 said that crossing for the instant production of new va- 

 rieties is most certain to give valuable results in those 

 species which are propagated by buds, because the initial 

 individual differences are not dissipated by seed reproduc- 

 tion. This is especially true of crossing between distinct 

 species ; for in such violent crossing as this the offspring 

 is particularly likely to be unstable when propagated by 

 seeds. The results of hybridization appear to be most 

 certain in those plants grown under glass, and in which, 

 therefore, the selection of the seed-parents is most care- 

 fully made, and where the conditions of existence are 

 most uniform. The most remarkable results in hybridiza- 

 tion yet attained are with the choicer glass-house plants, 

 such as orchids, begonias, anthuriums, and the like. 



The more violent the cross, the less is the likelihood 

 that desirable offspring will follow. Species which refuse 

 to give satisfactory results when hybridized directly or 

 between the pure stocks, may give good varieties when 

 the " blood" has become somewhat attenuated through 

 previous crossings. The best results in hybridizing our 

 native grape with the European grape, for example, have 

 come from the use of one parent which is already a hy- 

 brid. Two notable examples are the Brighton and Diamond 

 Grapes, raised by Jacob Moore. The Brighton is a cross 



