TABLE  XVII.
------------------------------------------------------------

-
|No. of    |         | Ave. to
|fertile   | No. of  | fertile
Parentage.                    |marriages.|children.|marriage.
------------------------------------------------------------

-
First cousin.  Gene.           |   125    |   672   |    5.4
First cousin.  Cor.            |   150    |   759   |    5.1
Double cousins and uncle-niece|     9    |    39   |    4.3
Other consanguineous          |   333    |  1605   |    4.8
Non-related                   |   676    |  3417   |    5.1
Ch. of 1st cousins            |   294    |  1395   |    4.7
All consanguineous            |   617    |  3075   |    5.0
All non-related               |   970    |  4812   |    5.0
------------------------------------------------------------

-

The report of Dr. Bemiss, and the report of the Ohio commission[47] which he quotes, give the following figures:[48]

TABLE XVIII.
-------------------------------------------------------
| No. of   |         | Ave. to
| fertile  | No. of  | fertile
Parentage.              |marriages.|children.|marriages.
-------------------------------------------------------
1st cousins or nearer[A]|   660    |   3363  |    5.0
More distantly related  |   119    |    572  |    4.8
Non-consanguineous      |   125    |    837  |    6.7
Ohio consanguineous     |   155    |   1021  |    6.6
Ohio non-consanguineous |   200    |   1375  |    6.9
-------------------------------------------------------
[A] Includes double-cousins and uncle-niece marriages.

[Footnote 47:  Appointed to ascertain the number of the deaf and dumb, blind, idiotic and insane within the State.]

[Footnote 48:  See Bemiss, in Trans. of Am.  Med.  Asso., vol. xi, 1858, pp. 420-425.]

The comparatively low averages of the consanguineous marriages from Bemiss may easily be accounted for by the fact that the cases were highly selected so that nearly one-third of the children were in some way defective, and the parents in many cases were far below the average in vitality.  The “more distantly related” are in a still lesser degree representative of the class, since out of a greater possibility of choice a smaller number were chosen.  The “non-consanguineous” were supposed to be near the average in vitality and fertility.

In Norway, according to Uchermann, the consanguineous and the non-consanguineous marriages are equally fertile, averaging 6.1 children per marriage;[49] and in a Black Forest village Tenckhoff found an average of 4.6 children to each consanguineous marriage as against 3.5 to each non-consanguineous marriage.[50] In regard to the youthful death-rate among the offspring of consanguineous marriages, comparison with non-related marriages is more feasible.  I have counted in each case all those children who are known to have died under the age of twenty.  This age was taken for the sake of convenience, and to include all children indefinitely specified as having “died young.”  The results are given in Table XIX: