THEORY OF STATISTICS. 
TABLE IV.—Showing the Frequencies of Different Combinations of 
Hye-colowurs in Father and Son. 
(Data of Sir F. Galton, from Karl Pearson, Phil. Trams., A, vol. cxcv. 
(1900), p. 188 ; classification condensed.) 
1. Blue. 2. Blue-green, grey. 3. Dark grey, hazel. 4. Brown. 
FATHER’S EYE-COLOUR. 
: : Total. 
194 70 41 30 335 
: 83 |, 124 a | sos 
=. 95 | ot 55 23 137 
=? i “3 43 109 244 
Total 358 264 20 198 1000 
The following are the ratios of the frequency in column m to 
the sum of the frequencies in columns m and m + 1 :— 
CoLumMNs 
1 and 2. 2 and 3. 3 and 4. 
0-735 0-631 0-577 
0-401 0-752 0-532 
0-424 0-382 0-705 
0-609 0-456 0-283 
The order in which the ratios run is different for each pair of 
columns, and it is accordingly impossible to make the table 
isotropic. The distribution of signs of association in the several 
tetrads is— 
The distribution is a curious one, the associations in tetrads 
round the diagonal of the whole table being so markedly positive 
and those in the immediately adjacent tetrads equally markedly 
negative. Neglecting the other signs, this is the effect that 
would be produced by taking an isotropic distribution and then 
increasing the frequencies in the diagonal compartments by a 
sufficient percentage. Comparison of the given table with others 
from the same source shows that the peculiarity is common to 
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