INHERITANCE OF ABNORMAL VENATION. 19 
Fig. 52 shows graphically the results of the three sorts of matings: 
normal X normal, normal < abnormal, and abnormal < abnormal. The 
first should give one mode at zero abnormality and another at 25 per 
cent abnormality on the assumption that normality is dominant in the 
sense in which the term is now used in Mendelian literature. These 
modes would represent the results of DD x DD and DR X DR, respec- 
tively. They are present, but the curve runs all the way up to 65 per 
cent abnormal. The second should give one mode at zero and another 
at 50 per cent, representing the results of DD x RR and DRXRR, respec- 
tively. The mode at 5 per cent is marked and might be explained as the 
48 - 
46 : 
30 : 
wn 28 — — Normal x Normal : 
—~—-Normal x Abnormal : 
seeeeees Abnormal x Abnormal 
Percentage of abnormal individuals 
Fie. 52. 
result of ‘‘incomplete dominance,’”’ a thing which is itself badly in need 
of a Mendelian explanation. At 50 per cent thereis a drop in the curve 
where there should be a mode. There is a strong mode at 75 per cent, 
where there should be none. This is true both when the male is the 
normal parent and when the male is the abnormal one (see fig. 58). 
Abnormal < abnormal should have but a single mode, 100 per cent (or 
95 per cent as the figure is drawn), representing the result of RR x RR. 
Such a mode is pronounced in the curve, being chiefly made up of the 
families of the abnormal strain after generation VII, but the curve 
reaches all the way to zero. 
These data are analyzed in tables 24 to 35, so that there is no need of 
a further text description of them. They are taken from the early part 
