[Footnote 13:  See article in Cincinnati Gazette, Jan. 22, 1895.]

CHAPTER II

RATIO OF THE CONSANGUINEOUS TO ALL MARRIAGES

Towards determining the average frequency of occurrence of consanguineous marriages, or the proportion which such marriages bear to the whole number of marriages, little has as yet been done in this country.  Professor Richmond Mayo-Smith estimated that marriages between near kin constituted less than one per cent of the total,[14] and Dr. Lee W. Dean estimates that in Iowa they comprise only about one half of one per cent.[15] But these estimates are little more than guesses, without any statistical basis.

[Footnote 14:  Statistics and Sociology, p. 112.]

[Footnote 15:  Effect of Consanguinity upon the Organs of Special Sense, p. 4.]

In several European countries such marriages have been registered, though somewhat spasmodically and inaccurately.  According to Mulhall[16] the ratio of the consanguineous among 10,000 marriages in the various countries is as follows: 

TABLE I.
-----------------------------------
Country.| Ratio. | Country.| Ratio.
-----------------------------------
Prussia |  67    | Alsace  |  107
Italy   |  69    | France  |  126
England |  75    | Jews    |  230
-----------------------------------

[Footnote 16:  Dictionary of Statistics, p. 383.]

According to Uchermann the ratio is 690 or 6.9 per cent, including marriages between second cousins and nearer.[17] Dr. Peer says that 4 per cent of the marriages in Saxony are consanguineous.[18] The ratio seems to be increasing in France but diminishing in Alsace and Italy, as indicated in Table II.[19]

[Footnote 17:  Les Sourds-muets en Norvege.  Quoted by Feer, p. 9.]

[Footnote 18:  Der Einfluss der Blutsverwandschaft der Eltern auf die Kinder, p. 9.]

[Footnote 19:  Mulhall, Dictionary of Statistics, p. 383.]

TABLE II.
---------------------------------------------------------
Country.| Date.  |Ratio.[A]| Country.|  Date.  |Ratio.[A]
---------------------------------------------------------
France  | 1853-60|  97     | France  | 1861-71 |  126
Alsace  | 1858-65| 143     | Alsace  | 1872-75 |  107
Italy   | 1868-71|  84     | Italy   | 1872-75 |   69
---------------------------------------------------------
[A] Per 10,000.

In Italy the ratio varies greatly in different parts of the country.  Mulhall gives the following figures for the years 1872-75: 

TABLE III.
------------------------------------------
Province.| Ratio.[A]| Province.| Ratio.[A]
------------------------------------------
Venice   |  24      | Sicily   |  117
Naples   |  30      | Piedmont |  131
Lombardy | 100      | Liguria  |  183
------------------------------------------
[A] Per 10,000.

It will be noted that the lowest ratios are in provinces where the urban population is comparatively large.  Wherever statistics have been gathered it is the rule that the percentage of consanguineous marriage is greater in rural than in urban districts.  Table IV, also from Mulhall, illustrates this point.