A compilation of data on the hereditary aspects of deafness presented at a conference in 1883 by Alexander Graham Bell, the document contains records of familial occurences of deafness and marriage statistics. Tables indicate that within schools for the deaf many students had the same family name; it was considered highly probable that a considerable proportion of deaf mutes belonged to families containing more than one such person. Of 5,823 deaf mutes from various parts of the county, 29.5% were known to have deaf and dumb relatives. Records from two institutions showed that about one half of the students born before 1840 had married; of 1,089 from five schools who had married, an increased proportion had married other deaf mutes. Indications were found that a hereditary tendency toward deafness, as indicated by the possession of deaf relatives, was a most important element in determining the production of deaf offspring, and that the proportion of deaf mute children born to deaf mutes was many times greater than the proportion born to the people at large. Additional information is provided and includes charts, graphs, and family trees. (RJ).