[SAUNDERS] INHERITANCE IN BARLEY 23 



903H. This belongs to type 11(C) and is really an intermediate 

 so far as rows are concerned. Its progeny belonged to types I and II. 



924T. This plant belongs to type 11(B), as it produced types II 

 and IV. However, most of the heads on the parent plant had no 

 trace of hoods at all. The progeny, as far as they belonged to type II, 

 were studied with much care. Out of 26 plants, 4 carried very slight 

 traces of hoods on some of the basal bracts. The other 22 plants 

 had no sign of hoods anywhere. These are striking instances of the 

 "potentially hooded" condition. 



903F. This is another example of a potentially hooded plant. 

 It had only two (abortive) hoods on the whole plant. It proved to 

 belong to type 11(B), giving types II and IV only in its progeny. 

 The hoods on the plants belonging to type II were very scarce, but 

 were more numerous than on the parent. 



902H. This proved to belong to type III (two-row bearded) 

 though it carries several extra kernels. Its progeny were not quite 

 uniform but always had some extra kernels. The number of these 

 varied from 6 to 17 to the head. 



908L. This also is of type III, and carries one or two extra ker- 

 nels on each head The next generation gave some plants which were 

 free from these extra kernels, while others closely followed the parent. 



908M. This shows the regular form of type III, the lateral 

 rows having no kernels at all 



The central head in plate D belongs to type IV. It is a small 

 but typical Arlington head, as far as awns are concerned, but the 

 lateral rows of kernels are incomplete. It no doubt belongs to 

 type IV(B). 



924S. This belongs to type IV and shows how well developed 

 the awns sometimes are. The lateral rows are almost full of kernels. 

 Seeds sown from this plant produced types III and IV, showing that 

 it belongs to type IV(B). 



905F. This plant was found, by a study of its progeny, to 

 belong to type IV(B), although the awns are unusually well developed 

 for this type. The longer awns and the gaps in the rows are sufficient 

 proof that this is really a heterozygous form and not the true Arlington 

 type. 



The right-hand head on this plate belongs to type IV(A), and is 

 a typical Arlington head. As the lateral rows are quite filled with 

 kernels this plant will breed true to the one type. 



A comparison between 902H and 908L on the one hand and 

 924S and 905F on the other hand will demonstrate how difficult it 

 is to distinguish, by the eye, between types III and IV. 



