BREEDING FOR NEW USES. 41 



tion. B}^ self-fertilizing or crossing the flowers on these plants of the 

 first generation greater variation is produced, and, for a few genera- 

 tions, continued new forms may be expected to result from the varia- 

 tion inaugurated by the hybridizing of the two species or genera. 

 Variation can often be profitably increased by crossing the hybrid 

 back on one of the parent species or by crossing two hybrids of differ- 

 ent or partially different parentage. In some cases hybrids persist in 

 i-emaining intermediate between the two parental forms or in taking 

 and retaining the characteristics of one or the other of the parents. 

 In this case the only utility of the hybrid may be to serve as one 

 parent to use in making still another hybrid; or it may be wise 

 at once to discard it, that more attention may be given to hybrids 

 which show variation. Garton Brothers, of England, who have done 

 most commendable work in producing hybrids among field crops, say 

 that "the effort should be to secure a reaction," meaning that those 

 crosses are most desirable which cause excessive variation or a multi- 

 plicity of tj'pes, some of which will probably be found useful new 

 forms from which superior varieties may be developed. Where the 

 relationship is very distant the hybrids are likely to be weak in 

 fecunditj^ or in some other vital characteristic, though progeny of 

 great value sometimes occurs. 



BREEDING FOR SPECIAL AND NEW USES. 



While our best efforts should be directed toward better fitting our 

 staple crops and our commonly used plants for their accustomed fields 

 of usefulness, there are special and new uses for plants which should 

 receive attention at the hands of plant breeders and plant introducers. 

 This work, which was emphasized in previous paragraphs, can be 

 accomplished in part by selection, but even more thoroughl}' in most 

 cases by hybridization, followed by selection. To extend the growth 

 of some species to regions in which thej^ do not now succeed, varieties 

 are needed which will endure more cold, or more heat, or more 

 drought, or more wind, or more alkali, oi-be adapted to other features 

 of new surroundings. Many of the changes needed for these [)ur- 

 poses could not be bred into the varieties, especially in case of close- 

 fci't ilized species, b}^ selection alone. New varieties must be created 

 l)y hybridizing. The work is sometimes quickly accomplished, and 

 sometimes results come vei-v slowlv oi- not at all. Resistance to dis- 

 case is a quality of superlative importance in manjMnstances. Sugar 

 l»eets have been enriched in their percentage of sugai- content, and 

 made more valuable by lessening the amount of solids other than 

 sugar which are expensive to remove in the manufacture of pure 

 sugar. Since sugar beets are an open-fertilized s[)ecies, the natural 

 ci-ossing of the plants has doubtless been a powerful agent in creat- 

 ing this new value in the roots. Corn is being nuide a belter food by 



