IMPROVEMENT OF WHEAT 43 



also arise characteristics so new in kind and degree that they 

 can hardly be considered as a mere combination of any char- 

 acteristics found in the parents. All of the so-called " botan- 

 ical" classes of wheat have been produced by hybridizing two 

 varieties, a fact which "certainly indicates blood relation- 

 ships between the classes of wheats. " 



Since the qualities originated by hybridization must be de- 

 veloped by selection, it may take years before the value of the 

 hybrid can be determined. The advantage in large numbers 

 lies in the fact that "only one individual in several thousand 

 has marked power to produce a valuable strain." These in- 

 dividuals have been called the " Shakespeares of the species," 

 and the labor of eliminating by selection all of the other in- 

 dividuals is 99 times that of producing the hybrids. 1 By the 

 usual method, the seeds to be tested and selected are planted 

 individually in rows 4 or 5 inches apart. If any promising 

 plants develop, 100 seeds from each are again planted. These 

 groups of plants from single parents are called centgeners. 

 By means of selection, crossbred wheats can thus be reduced 

 in four or five generations to a type so uniform that little or 

 no variation will occur among plants in the field. Whether 

 they will retain their acquired characteristics has been ques- 

 tioned. Hybrids originated by Hays and Saunders seem to do 

 so. The question as to whether wheat will deteriorate under 

 self-fertilization is still an open one. 



In breeding a variety of wheat, the ideal to be held in mind 

 constantly is ' ' that it yield the largest possible amount of grain 

 of the best quality for the purpose desired under given con- 

 ditions." 2 In such a course botanical appearances seemingly 

 will take care of themselves. 



Historical. The sexuality of plants was proved experi- 

 mentally by Camerarius (1691). The first recorded hybrid was 

 produced by Thomas Fairchild (1719), an English gardener, 

 who crossed the carnation with the sweet william. The publi- 

 cations of Koelreuter (1761) paved the way for the work of 

 Thomas Andrew Knight (1800), the eminent English plant 

 physiologist, who has been called the father of plant breed- 



1 Hays, Yearbook U. S. Dept. Agr., 1901, p. 229. 



2 Scofleld, Algerian Durum Wheats, p. 7. 



