478 
Proceedings of the Royal Society of Edinburgh. [Sess. 
Parent. 
M. 
Offspring. 
(a, a). 
(a, b). 
(b, b). 
(a, a) 
(a, b) 
(b,b) 
4 2 
2 2 
2 
2 2 
2 2 
2 
2 2 
2 4 
giving fourfold distributions, 
Parent. 
N. 
Offspring. 
(a, a). 
(a, b). 
(b, b). 
(a, a) 
4 
3 
1 
(a, b) 
3 
5 
1 
3 
1 
1 
1 
1 
(b, b) 
3 
1 
4 
Parent. Parent. 
M. 
Offspring. 
10 
6 
6 
10 
N. 
Offspring. 
15 
5 
5 
1 
7 
leading to correlations 
M. r=' 441, 
N. rS-50'1, 
when calculated by the fourfold method. Thus, again, Mendelian principles 
do not lead to low correlations but to figures approximately equal to those 
found by observation. 
9. When more complex formulae are taken the result is nearly the 
same. Supposing that instead of one pair of zygotes the parents possess 
two or three, that is, we have 
Dominant. 
Recessive. 
Father. 
Mother. 
(a, a) 
(b, b) 
(c, c) 
(d, d) 
(e, e) 
(f, f) 
and let mating be random, then the correlation table in the case of two 
pairs of zygotes becomes 
Parents. 
Offspring. 
Two Pairs 
of Dominants. 
One Pair 
of Dominants. 
No 
Dominants. 
Two pairs . 
25 
10 
1 
One pair 
10 
12 
2 
None . 
1 
2 
1 
