484 
Proceedings of the Royal Society of Edinburgh. [Sess. 
It is to be noted that column 2 in Table ii. gives almost exactly the 
figures found by observation and would thus appear a possible expression 
of the facts, though it is more probably a mere coincidence, as will be 
shown later. 
18. Two more cases of importance remain to be considered: that where 
like mates unlike, and that where the dominant includes the hybrid. 
Taking that where like mates unlike and reversing the mating given in 
par. 13, we have : — 
Husbands. 
Wives. 
(a, a). 
(a, b). 
(b, b). 
(a, a) . 
a 
n 
n - a 
(a, b) . 
n 
2 n 
n 
(b, b) . 
n — a 
n 
a 
If the population of offspring be then found and the correlation cal- 
culated we find that — 
1 + 2 - 
r = 
2 3 + 2- 
Table of Values. {Hybrid distinct.) 
Value of 
a 
n ' 
Correlation, 
Husband 
and Wife. 
Correlation, 
Parent and 
Offspring. 
•ooo 
-•500 
•289 
•125 
- 375 
*347 
•250 
-•250 
•401 
•375 
- *125 
•452 
•500 
0 
•500 
•675 
•125 
•546 
•750 1 
•250 
•593 
•875 
•375 
•631 
1-000 
•500 
•671 
This table also gives the effect of assortive mating when it is positive as 
well as negative. 
19. When the dominant includes the hybrid and the assortive mating 
is confined to the mixture we have then a correlation table as the 
following : — 
