344 DWARFS IN GLUYAS EARLY ( WHEAT) HYBRIDS. 



T'or the present it will perhaps be best to limit the discussion 

 to these two series of hybrid progeny. 



Alone from the standpoint of the economical breeding for 

 improved varieties of wheats, it is plain that these dwarfs furnish 

 an obstacle which causes greater labour, as none of the dwarfs 

 thus far have shown to have any enonomical value, and especially 

 as thus far there is no criterion by which it can be established 

 beforehand whether an apparently normal individual from such 

 a progeny will give rise to dwarf forms ; the only method of 

 ascertaining this fact lies in the propagation of such individuals 

 for another generation. When, however, as it is thought, one 

 of our best parent strains, e.g. Gluyas Early, is frequently pro- 

 ducing this uneconomical factor in its progeny, it may be neces- 



" — U)»t/a r f 



— /Vo r mal 



Fig. 4- — Frequency Curve for Height of Plant (cm.). 57/; X 41". 



sary to enquire further into the matter to ascertain whether no 

 solution is possible. 



Such an investigation may also give rise to other factors of 

 importance. 



Be it here briefly stated that natural hybrids are produced 

 between dift'erent strains of wheat, and perhaps to a greater 

 extent than is generally believed to be the case. In one instance, 

 for example, the knowledge of dwarfness has been of assistance, 

 in so far as a selection was made from a variety of wheat which 

 evidently was nothing else but an F.i hybrid; and as was 

 apparent from the progeny, the paternal parent could be estab- 

 lished. In so far. then, it may be of use. 



However, as in the case of the 106 selections of the 36a 

 X 41 A, 42 gave rise to dwarfs, and in the case of 41 selections of 

 57& X 41a, 22 gave rise to dwarfs; so that, unless further selec- 

 tion is practised, these, even though having exceedingly desirable 

 qualities, cannot be propagated owing to this, from an economical 



