family of first cousins are the four grandparents of the mother of the pair A, the other four being outsiders. The other eight families each have eight great-grandparents; two of the families having among their great-grandparents the parents of one of the grandfathers of the pair A, but no other great-grandparent in common with the pair A; other two of the eight families having among their great-grandparents the parents of the other grandfather of the pair A; other two having among their great-grandparents the parents of one of the grandmothers of the pair A; the remaining two families having among their great-grandparents the parents of the other grandmother of the pair A; while in all cases the six remaining great-grandparents of each family are outsiders, in no way related, on our assumption, either to the eight great-grandparents of the pair A or to each other, except as connected in pairs by marriage. Now manifestly in such a case, which, save for the symmetry introduced to simplify its details, represents fairly the usual relationships between any family, its first cousins, and its second cousins, we should not expect to find any one of the ten other families resembling the pair A more closely in _all_ respects than would any other of the ten. The two first-cousin families would _on the whole_ resemble the pair A more nearly than would any of the other eight, but we should expect to find _some_ features or circumstances in which one or other or all of the second-cousin families would show a closer resemblance to one or other or both of the pair A. This is found often, perhaps generally, to be the case, even as respects the ordinary characteristics in which resemblance is looked for, as complexion, height, features, manner, disposition, and so forth. Much more would it be recognized, if such close investigation could be made among the various families as the naturalist can make into the characteristics of men and animals. The fact, then, that features of resemblance to man are found, not all in one order of the Simiadæ, but scattered among the various orders, is perfectly analogous with the laws of resemblance recognized among the various members of more or less closely related families.