INHERITANCE OF STRENGTH 169 



always hard and translucent whilst the Rough 

 Chaff is always opaque, soft and floury. Moreover 

 in the mill and bakehouse these varieties are also 

 very distinct from one another. The differences 

 are difficult to describe in non-technical terms, but 

 they are so marked that the veriest amateur can 

 distinguish between the flours, the doughs and the 

 bread from the two varieties. They provided 

 therefore more or less ideal material for the investi- 

 gation of the inheritance of strength. The F 2 

 generation of the cross showed segregation into 

 strong and weak forms roughly in the proportion 

 of three of the former to one of the latter. A series 

 of individual plants from this generation were 

 then grown on, and those which proved to be fixed 

 in all recognisable features were multiplied as 

 rapidly as possible with the object of carrying out 

 baking trials. These tests made on the F 4 genera- 

 tion of the cross showed that the endosperm of 

 the grain was either that of one parent or the 

 other and that it was never a blend of both. We 

 had then for the first time proof that the wheat 

 breeder could definitely undertake to build up 

 varieties possessing this characteristic hitherto 

 unknown amongst English wheats. But, simple 

 as it may appear to put this knowledge to practical 

 use, many difficulties have been met with in the 

 attempts to do so. Chief amongst these is the 

 fact that in the F 2 generations from many Fife 

 hybrids the segregation into strong and weak 



