PROFESSOR K. PEARSON AND DR, A. LEE ON 
118 
If we allow that it is from the theory of exclusive inheritance that we must seek 
results in the present cases, we see that for parental, collateral, and avuncular relation¬ 
ships we get quite excellent results, but that the grandparental relationship is some- 
what anomalous. A priori it might appear that reversion would aid us in increasing 
the correlation between offspring and remote ascendants. But, as I have shown else¬ 
where,*' this superficial view of reversion forgets that the parents as well as the 
offspring revert, and if we increase the grandparental correlation above '25, we at once 
reach difficulties in the values of the parental correlation, provided we adopt what 
appear to be reasonable assumptions as to reversion being a continuous and decreasing 
factor from stage to stage of ancestry. I am inclined accordingly to suspend judg¬ 
ment on the grandparental relationships, thinking that the smallness of the number 
of families dealt with in Mr. Galton’s data (200) may have something to do with my 
peculiar results. Meanwhile I shall endeavour to get the remaining six grandparental 
tables for thoroughbred horses worked out, and see whether they confirm the high 
values already found for the two maternal grandsires and offspring, or give an average 
value much nearer '25. 
That the reader may see at a glance the general results hitherto obtained in this 
and other papers, 1 append the following table of inheritance :— 
* See mv paper on “The Law of Reversion,” ‘Roy- Soc. Proc.,’ vol. 66, p. 140 et seq. 
Grammar of Science,’ second edition, 1900, pp. 486-96, “ On Exclusive Inheritance.” 
Also ‘ The 
