ically prepared. The material gathered
from such sources is very accurate in regard to the number of births,
youthful deathrate etc., but mental or physical defects are rarely
mentioned. The greatest objection to the utilization of this material,
however, is the amount of labor necessary in order to glean the
desired facts from the mass of irrelevant data. For example, in order
to find one case of first cousin marriage it is necessary on an
average, to examine the records of nearly two hundred other marriages.

The collection of data from personal sources is likewise open to grave
objections. Not only is the informant likely to be biassed, but the
cases which he will remember will be those in which something unusual
has occurred. Herein lay the fallacy in the conclusions of Dr. Bemiss.
I have endeavored to overcome this bias by restricting my requests
for information to genealogists and others who would more naturally
appeal to records, but my efforts have been only partially successful.

The number of cases of consanguineous marriage, embracing all degrees
of consanguinity, which I have collected from these two sources,
genealogies and correspondence, is 723, a number too small in itself
to establish any definite conclusions; but by using this material in
connection with other related data, I trust I may be able to add
something to the comparatively small amount of real knowledge which
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, Mars