CORRELATION I09 
above method of determining the value of a correlation 
coefficient was tested by arranging in a similar manner 
data with regard to stature which had already been 
treated in the form of a complete correlation table. 
The whole number of fathers was divided into two 
groups containing the individuals above and below a 
certain stature, and the same was done in the case 
of the sons. And the separation into two groups was 
made in several different ways by taking the dividing 
PARENTAL CORRELATION OF COAT COLOURS IN HORSES, 
FIiuigs. SrrgEs. 
Total. 
Colour. and Toker: ne 
Bay and darker ... eae 631 125 756 
Chestnut and lighter... 147 147 294 
Total eas nes 778 272 
line between the groups at various heights. By 
applying to the statistics disposed in these various 
arrangements the same method as was applied to the 
statistics of horse colour already referred to, values 
varying between 0°52 and o°6 were obtained for 
parental correlation ; whereas the value arrived at by 
the more usual and reliable method was 0'514. It 
would therefore appear that there is with this method 
a tendency to obtain too high a figure, as compared with 
that derived from the method of the complete correla- 
tion table. When this source of inaccuracy is taken 
