546 DWARFS IN GLUYAS EARLY (WHEAT) HYBRIDS. 



capacity, and if it is found that in the segregation some or ah of 

 the classes yield pure recessives, then naturally it may he con- 

 cluded that those classes giving this recessive dwarfness are 

 allelomorphs ; i.e., the pure normal height of such a class and 

 dwarfness forms an allelomorphic pair, and these, together with 

 such classes which may not give rise to dwarfness. make up this 

 compound quantitative characteristic. 



Naturally, then, a population may contain various allelo- 

 morphs, all combining to make up one characteristic such as 

 height, the allelomorphs being simply classes ranging between 

 various dimensions, so that with the natural variation in each 

 class it may be found difficult to distinguish whether an individual 

 belongs to the allelomorphic class having either a greater or a 

 less dimension, the more so as the possibility exists that each class 



Tc/a/ 



D^arj 



— tier ma i 



Fig. 6.— Frequency Curve for Weight of Grain (grm.). 57b X 4i"- 



representing an allelomorph need not have the same limits within 

 which it varies, and the natural variation in such classes may 

 cause individuals to appear as belonging to a higher or lower 

 class in height. 



From Table I it is apparent that the mean height ranges 

 between the normal heights of the parents in the 36a X 41 A 

 progeny ; the same holds true except in regard to the progeny of 

 parents yielding all-normal progeny. 



In comparing curves 1 and W . giving a comparison between 

 the frequencies of the height of parents (T), total, i.e.. ])arents 

 yielding dwarf progeny and normal progeny, (2) yielding dwarf 

 progeny, and (3) yielding normal progeny, it will be noticed that 

 the curves do not represent a population which breeds true to the 

 characteristic height, but gives an indication that for the character 

 height there are various populations to be considered. Moreover, 



