the world already possesses in regard to the marriage of kin.

In the course of my investigations I visited Smith's Island, in the
Chesapeake Bay, about twelve miles across Tangier Sound, from
Crisfield, Maryland, and nearly opposite the mouth of the Potomac.
Here is a community of about seven hundred people, who are principally
engaged in the sea-food industry. Their ancestors have lived on the
island for many generations and there have been comparatively few
accessions to the population from the mainland. As a natural
consequence the population is largely a genetic aggregation.
Consanguineous marriages have been very frequent, until now nearly all
are more or less interrelated. Out of a hundred or more families of
which I obtained some record, at least five marriages were between
first cousins. All of these were fertile, and all the children were
living and apparently healthy. Since over thirty per cent of the
inhabitants bear one surname (Evans), and those bearing the first four
surnames in point of frequency (Evans, Brad-shaw, Marsh, and Tyler)
comprise about fifty-nine per cent of the population, it will readily
be seen that comparatively few absolutely non-related marriages take
place. Yet in this community from September, 1904, to October, 1907,
or during the residence there of the present physician, Dr. P.H.
Tawes, there have been 87 births and but 30 deaths, the latter from
the usual causes. During this period there has not been a single case
of idiocy, insanity, epilepsy, deaf-mutism or even of typhoid fever on
the island.

The evidence gathered from various other isolated communities is very
conflicting. Huth describes a great many of them which have existed
for many generations without crosses without ill results. Other
writers quote instances where whole communities have become