No. 611] LINKED CHABACTEBS IN WHEAT CBOSSES 685 



as the macaroni parent was called 100 per cent, hard; a 

 grain as soft as the bread wheat parent was called per 

 cent, hard; all grains intermediate between these were 

 called 50 per cent. hard. A plant which produced 60 per 

 cent, hard grains, 30 per cent, intermediate grains and 10 

 per cent, soft grains would therefore be classified as 

 follows : 



.60 X 1.00 + .30 X .50 + .10 X = .75 = 75 per cent. hard. 



Spotted grains (grains containing well-defined areas of 

 opaque starch in an otherwise translucent grain) such as 

 occur frequently in the macaroni wheat and also among 

 the hybrids were treated as intermediate grains. After 

 classifying the seeds of each plant in this manner all 

 those which were over 66| per cent, hard were termed 

 hard wheats, those from 33^ to 66f per cent, hard were 

 classed as intermediate and all less than 33J per cent, 

 hard were classed as soft. 



In 1914 the two parents (Nos. 1 and 35) and of this 

 cross were grown with the following results: 



The ratio, W./T. of the plants of this cross, is thus 

 seen to be much nearer to the macaroni parent both in 

 average and distribution than it is to the bread wheat 

 parent. 



Table II shows this same study made for the F2 plants, 

 grown in 1915. 



A uniform correlation between the hardness of the 

 grain and the ratio of width to thickness of head is ap- 

 parent in Table 11. 



Table III gives the results of this same study for the 

 crop of 1916. There is again apparent a marked correla- 

 tion between the ratio of width to thickness of head and 

 the texture of the grain. It will be noticed that both in 

 1915 and 1916 the soft (0 per cent, hard) hybrids had a 

 higher average ratio W./T. than the sonora. It should, 

 however, be remarked that the hybrid softs were also 

 harder on the average than the pure number 35, but since 



