R H. COMPTON 



57 



Six-Rowed Barley. 



A few sowings were made with Hordeum heccastichum, var. pyrami- 

 datum. In this species all three flowers produced at each notch of the 

 spike are hermaphrodite and set seed. Thus there are three odd and 

 three even rows on each ear. The three rows in each case are called 

 "left," "middle," and "right": that row being called "left" which is 

 towards the left hand when the ear is held upright with the middle 

 row towards the observer. Diagram 2, which is partly ground-plan, 

 partly elevation, will make this convention clear. 



O 

 Q 



Diagram 2. 



The three odd rows in several ears gave in all 55 LH and 45 RH 

 seedlings: the ratio LHjRH being 122 (% LH=5o). Exactly the 

 same ratio was given by the offspring of the three even rows; the 

 numbers being 60 LH, and 49 RH. In Table IV, therefore, the two 



170 



1-282 



56-98 



Total 218 



" left " rows — odd and even — are added together, and the same is done 

 for the " middle " and " right " rows respectively. 



Thus, as in the two-rowed varieties, there is an excess of left- 

 handed offspring from all positions on the spike. The numbers studied 



