1921 - 22 .] 
On the Dominance Eatio. 
329 
Distribution of the logarithmic frequency ratio ^s = log of the allelomorphs of a dimorj)hic factor. 
Fig, 1. — &ech. \zdz 
Ztt 
represents the distribution when, in the absence of selection, fortuitous extinction is counterbalanced 
by mutation. Dominance Ration *2308. 
-12 -10 -8 -6 -4 -2 0 2 4 6 8 10 12 
2 
Fig. 2. — d/=| sech^i^ds ; 
represents the distribution when, in the absence of selection and mutation, the variance is steadily decaying 
owing to fortuitous extinction of genes. Dominance Ratio = ‘2500. This is the condition emphasised by 
Hagedoorn. 
