[SAUNDERS] INHERITANCE IN BARLEY 25 



could generally be depended upon as a trustworthy indication, but 

 this fact was not discovered until after some years of study. 



The number of plants belonging to the two types was counted 

 in some of the groups in the second generation. The totals obtained 

 were, 70 plants of type I and 249 of type II. This is not very close 

 to the expected ratio of 1:3, but the difficulty of classification was 

 very great, almost all possible kinds of intermediate forms being 

 present, some of which could not have been placed without a study 

 of their progeny. 



Colour of Kernel 



As two of the parents used in the above crosses were huUess, 

 one having yellow and the other green kernels, it was hoped to study 

 successfully the inheritance of these colours. A great deal of work 

 was done with very little result. It appears that one or more inter- 

 mediate shades may be produced. The great difficulty in this investi- 

 gation lies in the effects of weathering and diseases. In unfavourable 

 seasons colours sometimes become so dull that they cannot be identi- 

 fied. Such studies should be taken up under greenhouse conditions 

 or in a dry climate, with irrigation. 



Summary 



The points of chief interest brought out in this paper are as 

 follows : 



The existence is proved of a well-defined, heterozygous type of 

 six-row barley, intermediate, in regard to awns, between the fully 

 awned condition and the Arlington type- 

 It is proved that awnless types of six-row barley exist in which 

 hoods are practically absent and which must nevertheless be classified 

 as potentially hooded, because they fail to produce any awned de- 

 scendants and because among their progeny an occasional trace of an 

 abortive hood can be found, either in its normal position on the glume 

 or else on one of the basal bracts. 



It is shown that the six-row condition in barley is sometimes 

 almost completely dominant over the two-row state in the hetero- 

 zygous plants. 



Practical Results 



On account of the extreme brittleness of the heads of most 

 varieties of which Arlington is one parent, it is doubtful whether any 

 types of commercial value will be found among the crosses mentioned 



