Sept. 1, 1920 Fixed Intermediate, Hoy deum intermedium haxtoni 579 



all the kernels are of normal size, while in the other they are subnormal 

 or absent. This second division is separated into plants which have 

 lateral florets with awned or awn-pointed lemmas and plants in which 

 the lemmas of the lateral florets are awnless and more or less rounded. 

 Further subdivisions were based on the percentage of fertility of the lateral 

 florets. The nature of the six resulting classes is illustrated in Plates 103 

 and 104. It is readily apparent in Plate lofi that the three classes with 

 awned or awn-pointed lemmas on the lateral florets are easily separated. 

 It is just as apparent in Plate 104 that the accident of season or nutri- 

 tion can easily affect the classification of the segregates with rounded 

 lemmas. Errors of classification in this case happen to be unimportant, 

 for, as previously stated, the object of the F3 classification is only to 

 determine the nature of the Fj parent. This is made evident in all cases 

 by the classification used. To make this clear, one of the findings must 

 be anticipated. Of the six classes in which the Fg plants are divided, 

 three are of special importance in the interpretation. These are the fully 

 fertile long-awned, the high-fertility awnless, and the no-fertility awnless 

 classes. These represent the 6-rowed, the intermedium, and the 2 -rowed 

 barleys. In all cases the classification is sufficiently accurate to determine 

 which of these classes are to be found in the progeny of each Fj plant. 



Table I. — Classification of Sy F^ plants and their F^ progeny in a cross between Man- 

 churia and Svanhals barleys according to the nature of their lateral florets 



GROTJP I, PLANTS WmCH GAVE ONLY 6-ROWED PROGENY 



