particular defect appearing. Thus both classes of investigators may be
perfectly conscientious, and yet arrive at diametrically opposite
results. This theory is at least not to be contradicted by any facts
which have come to light in the present investigation.

Some interesting points are brought up in Dugdale's well-known study
of the "Jukes."[53] This family, of about 540 persons living in
northern New York, is descended from five sisters of unknown
parentage, who were born between 1740 and 1770. The name "Juke" is
fictitious, and is applied to all descendants of these five women,
little attempt being made to trace the male lines on account of the
excessive prevalence of illegitimacy.

[Footnote 53: R.L. Dugdale, _The Jukes_]

In this family consanguineous marriages have been very frequent,
perhaps partly because the Jukes came to be looked upon as pariahs and
could not associate on equal terms with other members of the
community. These marriages seem to have been fully as productive as
the average of the family, and the offspring of as high a grade of
intelligence. However, some individual cases are worthy of special
mention as illustrative of intensification of hereditary tendencies.

(1) An illegitimate son of Ada Juke married a daughter of Bell Juke.
He was a laborer, honest and industrious. She was reputable and
healthy, and her father had a good reputation, but her mother had
given birth to four illegitimate children before marriage, three of
whom were mulattoes. Thus in this marriage of first cousins, three out
of the four parents were of a low moral grade. As a result of this
marriage three sons and three daughters were born. Two sons were