98 Inheritance in Barley 



The deviation is thus about four times the standard error and 

 cannot, therefore, with assurance, be regarded as a fluctuation of 

 sampling. 



The abnormal rachilla forms found in the Praecox parent (see 

 above) made their appearance in F^. They were not confined to any 

 particular type or types of F2 (as 6-row, 2-row, intermediate, etc.), but 

 were found in a few cases in all the F2 types. Abnormal forms were 

 often difficult to classify, and this may possibly be the reason for the 

 very considerable divergence from the 3 : 1 ratio— a ratio for which the 

 remaining crosses vouch. 



Gross No. 45. 



Russian Chevallier, No. 7 x English Archer 



2-row 

 Smooth 



I 2-row 

 I Bristly 



JFj = ail bristly 



F2=M& plants. Bristly : Smooth =410 : 136 



= 75-l%:24-9°/o 



The agreement with 3 : 1 expectation is thus extremely close. 



Gross No. 35. 

 Eussian Goldthorpe, No. 10 x Inerme 



2-row 

 Smooth 



\ 2-row 

 \ Bristly 



i<'i = 30 plants ; all bristly 



JP'2=510 plants. Bristly : Smooth = 387 : 123 



= 75-8% :24-2%. 



Here again, the deviation from 3 : 1 expectation is well within the 

 standard error. 



From the above results it is concluded that : 



(a) One factor governs type of hair in rachilla. 



(/8) "Bristly" is dominant to smooth, the ^1 being apparently 

 identical with the " bristly " P^. 



(7) Possibly this same factor also governs the type of hair in the 

 glume, rachis segment, and lodicule. 



II. The Lateral Floret. 

 The barleys, i.e. the sub-species of Hordeum sativum Pers., are 

 placed in primary groups in accordance with the forms of their 

 lateral florets. In hybrid generations are encountered lateral florets of 

 forms other than those which characterise the recognised " varieties " 

 or sub-species of the barleys. To facilitate the description of hybrid 

 generations there is given [(A) — (G) below] an account of all of the 



