F. L. Engledow 99 



forms of lateral floret which have been found in those F^'s and their 

 parents, with which this paper deals. 



The various forms of the lateral floret : 



(A) Always fertile (i.e. forming a grain), the grain being nearly as 

 large as that formed by the median floret. The lateral is awned or 

 awnless in strict conformity with the median of the race concerned^- 

 This form of lateral characterises H. hexastichum (the 6-row and 4-row 

 barleys of the agriculturist). 



(B) Always fertile under normal conditions but the grain decidedly 

 smaller than that of the median floret. 



Two sub-species, viz. H. Hacdoni and H. transiens, possess this form of 

 lateral, and they constitute the race H. intermedium. In them, the 

 outer palea of the median bears a long awn while that of the lateral is 

 completely awnless, being rounded at the tip. Under adverse conditions 

 it not infrequently happens that some of the laterals — or even all — fail 

 to set grain. They are, nevertheless, quite perfect in stamens and 

 ovary, and the non-fertility is purely a physiological response to environ- 

 ment ; it has absolutely no genetic significance. 



(C) Fertile ; grain small, smaller than in the case of (B) ; outer 

 palea terminating in an awn which may be merely a point or up to 

 3 cm. long. This type is confined to hybrid generations and appears to 

 be a heterozygote. 



(D) Non-fertile but inflated; the outer palea pointed or shortly 

 awned. Like (C) it occurs only in hybrid generations and (see below) 

 is probably a heterozygote. Stamens and a reduced ovary are present. 



(E) Non-fertile but large and inflated ; outer palea always rounded 

 and devoid of an awn. Stamens and a reduced ovary are present. This, 

 again, occurs only in hybrid generations. 



(F) Non-fertile, of full length, but not inflated. The outer palea is 

 always rounded and awnless. Stamens and a very small shapeless 

 ovary are present. This type characterises the " distichum " barleys to 

 which the familiar malting varieties Archer, Chevallier, Goldthorpe, etc, 

 belong. Changes of environment, however pronounced, appear not to 

 be able to cause this type of lateral to set grain. 



(G) Non-fertile and extremely reduced. There is a small outer palea 

 and a vestigial inner one, but no traces of rachilla or reproductive 

 organs are to be seen. This is the Abyssinian or " decipiens " type. 



1 The 6-row type devoid of awns in both median and lateral florets is exemplified by 

 the variety " Nogenasi " which Ikeno (9) employed in a cross to determine the inheritance 

 of awns. 



