present, and it is well they do, inasmuch
as for the reasons already given there is greater probability of
degeneracy by means of such connections than among those not so
related by blood. But they present an instance of the imperfection of
human laws, it being impossible for any legal enactments to prevent
wholly the evil thus sought to be avoided. It would be better far, if
such a degree of physiological knowledge existed and such caution was
exercised among the community generally, as would prevent the
contraction of any marriages, where, from the structure and endowments
of the parties, debility, deformity, insanity or idiocy must
inevitably be the portion of their offspring whether they are more
nearly related than through their common ancestor, Noah, or not.

If we adopt Mr. Walker's views, it is easy to see how parents of near
affinities may produce offspring perfect and healthy, or the reverse.
He holds, that to secure satisfactory results from any union, there
should be some inherent, constitutional, or fundamental difference;
some such difference as we often see in the human family to be the
ground of preference and attachment; as men generally prefer women of
a feminine rather than a masculine type. All desire, in a mate,
properties and qualities not possessed by themselves. Now assuming as
Mr. Walker holds, that organization is transmitted by halves, and
that, in animals of the same variety, either parent may give either
series of organs, we can see in the case of brother and sister that if
one receives the locomotive system of the father and the nutritive
system of the mother, and the other the locomotive system of the
mother and the nutritive system of the father, they are essentially
unlike, there is scarcely any similarity between them, although, as we
say, of precisely the same blood; and their progeny if coupled might
show no deterioration; whereas, if both have the same series of organs
from the same parents, they would be essentially the same, a sort of
quasi identity would exist between them, and they are utterly unfit to
be mated. There might be impotency, or barrenness, or the progeny, if
any, would be decidedly inferior to the parents; and the same applies,
more or less, to other relatives descended from a common ancestry, but
more distant than brother and sister. Mr. Walker also holds that
where the parents are not only of the same variety but of the same
family in the narrowest sense, the femal