NOTES ON RECENT RESEARCH. 



897 



<3an improve Wheat by selecting the best from our standard Wheats. 

 (2) That still more can be accomplished if we create new qualities 

 by hybridising, and then seek, from among very many, those few plants 

 that will best perpetuate the desired quality." 



" The real value of variation lies in the ability of the plant to 

 produce plants which individually and in the aggregate yield more and 

 better grain than the average of the same variety. The yield of the 

 mother plant is a very uncertain indication of its use for the mother of 

 a new strain, just as ' Messenger's ' record as a trotting horse is no index 

 to his great value as the progenitor of the American breed of trotting 

 horses." 



Breeding by Hybridisation and Selection. 



" Most of the variation in plants has its origin in reproduction from 

 seed, the variation being, as a rule, the greater the more distant the 

 relationship between the two parents. 



" In breeding by selection alone the variations occurring naturally or 

 accidentally within the variety are depended upon. 



" In breed or variety- formation through the agency of hybridisation, 

 followed by selection, man plays almost a creative part. Where there is 

 no variation of such nature as desired, it is created by bringing together 

 two of the many forms which have varied from some ancestral form, yet 

 not so far but that they will cross-fecundate. The further they have 

 departed from ancestral characteristics and formed diverse qualities, the 

 more likely will their progeny exhibit new characteristics made up of 

 combining those which have become so radically different in the two 

 parents." 



Degree of Belationsliip in Crosses. 



With regard to the question of the alleged evils of very close breeding 

 — " in-and-in " — Prof. Hays maintains that even such close-fertilised 

 species as Wheat may be materially improved by the most incestuous 

 kind of inbreeding, carried on for many generations." Probably in this 

 case Prof. Hays was careful to select only the most healthy and 

 most fertile plants as parents. With regard to the increased vigour, size, 

 and value obtained by cross-breeding. Prof. Hays gives an apparent 

 exception to the rule. 



Certain Wheat "hybrids" at the Minnesota Station after a few 

 generations " became very weak, and finally ceased to produce seeds, 

 while other stocks from the same two individual parent plants were very 

 strong, and were the progenitors of some of our most promising new 

 Wheats." This suggests that both vigour and fertility are themselves 

 subject to variation like other characters. 



Hybrids and Crosses defined. 



Prof. Hays follows the lead of Messrs. Swingle and W^ebber when 

 he defines the term "hybrid" to mean " a plant resulting from cross- 

 fertilising plants differing in their relationships, whether that difference is 

 great, as in species or even genera, or comparatively slight, as in distinct 

 varieties." 



This is not the definition usually employed in Europe, where the 

 term "hybrid" is generally confined to the product of distinct species and 



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