Page:Memoir upon the formation of a deaf variety of the human race (microform) (IA cihm 08831).pdf/19

14 not all the cases in which we would anticipate that intermarriage might be productive of deaf offspring. The late Dr. Harvey L. Peet states, as the result of his researches, that the hearing brothers and sisters of a deaf-mute are about as liable to have deaf children as the deaf-mute himself. It is only reasonable to assume that a tendency towards deafness exists in a family containing more than one deaf-mute, so that if hearing persons belonging to such families were to intermarry, or were to marry deaf-mutes—or if a consanguineous marriage were to take place in such a family—we would not be surprised if some of the offspring should be deaf. In addition therefore to the 20,474 deaf-mutes referred to above, we must include the hearing and speaking members of their families before we can form an adequate conception of the number of persons who possess a predisposition towards deafness.

It will thus be seen that we have abundant materials in the United States for the formation of a deaf variety of the human race by selection in marriage.