Marriages of the Deaf in America, chap. v.
Of the 17 children of first cousins reported on my circulars as either totally or partially deaf, 9 are known to have had deaf ancestors.
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.