22 



Breeding of Wheat. 



present to every one of the latter, the distribution of the two 

 forms being" uniform in the eight types mentioned above. 

 Strength in this case, then, proved to be simply dominant to lack 

 of strength. In the following season a number of pure strong 

 types were isolated and grown on again the following year, in 

 order to obtain sufficient grain for tests in the bakehouse. The 

 results of these tests confirmed the view arrived at from an 

 examination of the grain of the F. 2 generation, and left no doubt 

 that the strength of these, hybrids was of the same order as that 

 of the parent Red Fife. 



In many other cases the simple Mendelian ratios are not so 

 readily ascertainable, owing to the varieties chosen as the weak 

 parents producing semi-translucent grain. Under such con- 

 ditions the well-known chewing test of the wheat buyer is 

 generally sufficient to show that segregation has occurred, and 

 to enable the breeder to pick out the strong types for further tests. 



Whilst these investigations were in progress some of the late 

 W. Farrer's Fife crosses were being obtained in sufficient bulk 

 for baking tests. These also proved to be "fully as strong as 

 Fife." Thus the facts at our disposal seem to warrant the state- 

 ment that strength is a unit character. Complications may and 

 probably do exist, much as they do with the colour characteristics 

 of wheat, but of this nothing - is known at present ; so far the only 

 exception taken to this view has been based on cases in which 

 the actual baking strength of the parent plants is unknown. 



The strong wheats of the world are at present cultivated almost 

 exclusively in countries in which the yield per acre is small ; 

 where large yields are the rule the weaker types only are in 

 general cultivation. It has consequently been assumed that 

 strength and lowness of yield are correlated with one another. If 

 this view be correct the combination of heavy yield with strength 

 is an impossible one. At present little evidence can be brought 

 forward from one side or the other, though it is worth noting 

 that in some few districts in England Red Fife crops as well as 

 Square Head's Master. Such fresh evidence as can be brought 

 forward at this stage points, however, to the incorrectness of the 

 general view, and seems to show that a heavy crop of good 

 quality is by no means an impossibility. 



The best proofs of its possibility or otherwise would be afforded 

 by a detailed study of the inheritance of yielding capacity, a matter 

 on which it must be admitted we know little at present. That it 

 is a unit character is perhaps indicated by the fact that some 

 varieties are consistently heavier yielders than others even under 

 a wide range of variation in the conditions. For instance, Square 

 Head's Master has, on this account, gradually driven such varieties 

 as Red Lammas, Chiddam, Talavera, &c, practically out of 



