TABLE XXXIV. ---------------------------------------------------------- | | Marriages | | | resulting | | | in deaf | | | offspring | Deaf children |Number|-----------|------------------ Consanguineous |of | | | |Per Marriages |mar- | |Per | |Number|Cent of the Deaf. |riages|Number|Cent|Number|Deaf |Deaf ---------------------------------------------------------- First cousins | 7 | 4 | 57.| 26 | 7 | 27. Second cousins | 5 | 3 | 60.| 25 | 10 | 40. Third cousins | 1 | 1 | -- | 1 | 1 | -- "Cousins" | 14 | 3 | 21.| 36 | 7 | 19. Nephew and aunt | 1 | 1 | -- | 4 | 3 | 75. Distantly related | 3 | 2 | 67.| 8 | 2 | 25. ---------------------------------------------------------- Total consanguineous| 31 | 14 | 45.| 100 | 30 | 30. Not consanguineous, | | | | | | or no information |3,047 | 286 | 9.|6,682 | 558 | 8. ---------------------------------------------------------- Grand total |3,078 | 300 | 10.|6,782 | 588 | 9. ---------------------------------------------------------- Obviously percentages based on these figures are of little value of themselves, especially since Dr. Fay's cases are not entirely typical, but in general this table points us to the same conclusion that we have reached by other means, namely that where a tendency toward deafness exists, a consanguineous marriage is more likely to produce deaf children than a non-consanguineous marriage. If more figures were available the percentage of deaf children would probably increase with the nearness of consanguinity and the number of deaf relatives, but with the present data a further analysis has no significance.[91] [Footnote 91: Mr. Edgar Schuster (_Biometrika_, vol. iv, p. 465) finds from Dr. Fay's statistics that the average parental correlation (parent and child) of deafness is: paternal, .54; maternal, .535. English statistics of deafness give: paternal correlation, .515; maternal, .535. The fraternal correlation from the American data is .74 and from the English .70. See _infra_, p. 92.] If, then, consanguineous marriages where relatives are deaf have a greater probability of producing deaf offspring, and also a greater probability of producing plural deaf offspring, than ordinary marriages, and two thirds of the congenitally deaf offspring of consanguineous marriages do have deaf relatives, it does not seem necessary to look beyond the law of heredity for an explanation of the high percentage of the congenitally deaf who are of consanguineous parentage.