191 1 - 12 . J On Inheritance of Hair and Eye Colour. 
Thus 
denotes 
D 
D 
2 
a 
b 
a b 
B 
b 
or more shortly 
d 
d 
c 
d 
c d 
B 
b 
a 
2 
2 ac 
DD 
BB ! 
2 ab 
DD 
B b 
DD 
hb 
D d 
BB 
2ad 
+ 2 be 
D d 
B b 
2bd 
m 
i,b 
dd 
BB 
Zed 
dd 
B b 
d 2 
dd, 
bb 
463 
Each of the four sides of the complete expression is the square of the 
corresponding terms of the contracted expression, and the term in the 
middle the sum of twice the product of the diagonal elements. 
One or two other examples of the rate at which stability is approached 
in one generation are shown in the following table : — 
Table II., showing Rate of Approximation to a Stable Population. 
Form of Population. 
Value of 
m 
n ' 
Value of 
ad , 
T-at 
be 
Commencement. 
Value of 
— after 
be 
One Generation. 
9 -5 
1 1 
2 
9 
18 
15-6 
11 1 
1 1 
2 
9 
11 
10-5 
10 1 
1 1 
2 
9 
10 
976 
\/10 1 
1 ViO 
2 
9 
10 
9-67 
9-5 1 
1 1 
f 
1 
9 
9-5 
9-46 
5 1 
1 1 
f 
3 
5 
4T 
4 1 
1 1 
2 
3 
4 
37 
