24 THE ROYAL SOCIETY OF CANADA 



Plate E shows two magnified heads which carry hoods (more or 

 less developed) at the tips of the basal bracts. The head marked S 

 belongs to type II. One or two traces of hoods are seen on the median 

 row in addition to those situated on the basal bracts. The head 

 marked T belongs to type I. The photograph shows clearly the 

 great development of hoods usually occurring in this type. Some 

 of the basal bracts carry indications of hoods — a very unusual feature 

 in plants of type I. 



Cross No. 910 



The third cross was made between Arlington (female) and 475M 

 (male). The latter is a two-row bearded sort which retains its hull. 

 A head taken from a plant of the first generation is shown in the 

 photograph as No. 910. All the plants of this parentage had rather 

 long heads which must be described as six-row, however much one 

 might wish to support the belief in the dominance of the two-row 

 state. But these heads are longer and narrower than most six-row 

 varieties. The awns on the median rows are two inches or more in 

 length, while the four lateral rows are awnless. 



When seeds from these plants were sown, two types were obtained : 

 type I with only two rows of kernels and strongly awned, and type II 

 resembling rather closely the parent plant. More critical examination, 

 and a study of the progeny of type II, revealed the fact that this case 

 is similar to the one above related. There are here really two kinds of 

 plants, one a heterozygous form practically identical with the parent, 

 designated as type 11(A) and the other a homozygous form marked 

 type 11(B), which is indistinguishable from the original Arlington. 

 As a rule the lateral rows in type 11(A) are so well filled with kernels 

 that one is tempted to say that the six-row condition is dominant. 

 But there is always a slight incompleteness in these rows at the base 

 of the head, showing that perfect dominance does not occur. This 

 type is characterized also by a development of the awns intermediate 

 between that of type I and of the Arlington barley, type 11(B). 



The photograph (plate F) shows typical heads of types I, 11(A) 

 and 11(B). The difference in length of awns is very clear and one 

 can also see two empty glumes at the base of the head of 11(A), while 

 the head 11(B) ife completely filled. 



As in the group of crosses studied above, heads were found in 

 this group v/hich, though carrying quite a number of kernels in the 

 lateral rows, bred true. These had to be classed as belonging to 

 type I, though the difference between type 11(A) and these abnormal 

 members of type I was very slight. The development of the awns 



