506 Proceedings of the Royal Society of Edinburgh. [Sess. 
Calculated by the product method, though, this does not seem specially 
applicable here ; r = *337. By the fourfold division r* = '393, if the reds be 
taken on the one hand and the reds with white on the other. The parent- 
ages, however, are very unequal. If each be raised to 100 the correlation 
falls to r — *269. So that even among the dominant class there is a consider- 
able hereditary influence. On what basis it is to be explained there are 
not sufficient facts to indicate. There must be great variation in the zygote 
constitution and a certain amount of dominance in the dominant class, but 
to what it amounts would require much investigation. 
Colour Inheritance in Greyhounds. 
( Biometrika , vol. iii. p. 245. Barrington and Pearson.) 
The colour of greyhounds is somewhat complex; the classes used by 
Barrington and Pearson are : (1) red, (2) brindle, (3) white, (4) fawn, (5) 
pure black, and (6) mixed black. The exact relationship of these colours 
is not easily seen from the nature of the offspring. None are clearly 
dominant, and the hybrid must be largely separated from both dominant 
and recessive. The fanciers seem to derive the present stock from a 
mixture of at least three races, red, black, and white, and thus on a Mendelian 
mechanism the correlation coefficients should be high. The parental 
assortive mating obtained by the mean square contingency method is about 
r = ’ 20, but its nature is unknown, so that its effect on raising or lowering 
the correlation coefficient cannot be estimated. The actual correlations 
obtained by the mean square contingency are as follows : — 
Correlation between Parent and Offspring. 
Unselected Offspring. 
Offspring selected 
for Record. 
Sire and Dog 
•512 
•474 
Sire and Bitch . 
•579 
•404 
Dam and Dog . 
•505 
•485 
Dam and Bitch . 
•532 
•499 
Mean . 
•532 
•466 
Here two classes of correlation are given: one for the whole litters 
taken at birth and the second for the offspring selected for record. The fall 
in the correlation is noticeable. The value in the first case is not far from 
