TABLE XXXIII. ------------------------------------------------------------------- | Percentage having deaf children. |--------------------------------------- Class of Deaf Relatives. | |Totally |Partially |Congenitally |Total.|deaf. |deaf. |deaf. ---------------------------|------|--------|----------|------------ (a), (b) or (d) | 1.4 | 2.4 | 1.1 | 5.0 (d) | 3.2 | 3.3 | 2.6 | 6.4 No (d) | 1.1 | 1.4 | 1.0 | 2.5 (a) and (d) | 6.3 | 6.7 | 4.3 | 7.8 (d), but no (a) | 2.2 | 2.2 | 2.0 | 4.9 (a), but no (d) | 1.4 | 2.3 | 1.3 | 2.6 No (a) or (d) | 0.9 | 1.0 | 0.9 | 2.3 (a), (b) and (d) | 9.5 | 9.9 | [A] | 9.0 (a), (d), but no (b) | 5.5 | 5.9 | 3.6 | 7.4 (b), (d), but no (a) | 2.5 | 2.4 | [A] | [A] (d), but no (a) or (b) | 2.2 | 2.2 | 2.0 | 5.2 (a), (b), but no (d) | 1.9 | 3.1 | 1.7 | [A] (a), but no (b) or (d) | 1.3 | 2.1 | 1.2 | 2.8 (b), but no (a) or (d) | 1.0 | 1.6 | 1.0 | [A] No (a), (b) or (d) | 0.9 | 1.0 | 0.9 | 2.6 ---------------------------------------------------------------- [A] Percentages not given where base is less than 100. Symbols: (a) deaf brothers, sisters or ancestors; (b) deaf uncles, aunts, cousins, etc.; (d) deaf husbands or wives. The striking feature of these percentages is the regularity with which they increase in proportion as the number of deaf relatives increases, until among the 242 persons who have (a), (b) and (d) relatives, 23 or 9.5 per cent also have (c) relatives. A consanguineous marriage within a family tainted with deafness would have the same effect as doubling the number of deaf relatives, which as we have seen greatly increases the percentage having deaf children.