It is thus seen that 9.7 per cent of the marriages of the deaf result in deaf offspring, and that 8.6 per cent of the children born of them are deaf--proportions far greater than for the the population generally.[55] A striking fact to be noted, however, is that these proportions are greater when one parent is deaf and the other hearing than when both are deaf. The percentage of marriages resulting in deaf offspring when only one parent is deaf is 12.5, and when both are deaf, 9.2; while the percentage of deaf children born of them when only one parent is deaf is 9.8, and when both are deaf, 8.4. This is apparently a very strange result, though it probably may be accounted for in some part on the theory that it is not so much deafness itself that is inherited, but rather an abnormality of the auditory organs, or a tendency to disease, of which deafness is a result or symptom, and that with different pathological conditions in the parent there is less likelihood of deafness resulting. The most significant part of the results seems to be found, as before, in respect to whether or not deaf parents are themselves congenitally deaf or have deaf relatives. On the one hand, when one or both of the parents are adventitiously deaf, the percentage of marriages resulting in deaf children is 5.6, and the percentage of deaf children is 4.2; when both parents are so, the percentages are lower: 3.5 and 2.3. The percentages rise when one parent is adventitiously deaf, and the other congenitally: 8.1 and 6.5. In respect to deaf relatives of parents, the percentages are very low when neither has such relatives: 2.3 and 1.2. The lowest percentages of all are in the case where both parents are adventitiously deaf and neither has deaf relatives: 0.7 and 0.3. On the other hand, we find the proportion of marriages resulting in deaf offspring and the proportion of deaf children much greater when there is congenital deafness in one or both parents, when one or both have deaf relatives, and greatest of all when these influences are combined. When one or both parents are congenitally deaf, the percentage of marriages resulting in deaf offspring is 13.1, and the percentage of deaf children is 12.1; when both parents are so, the percentages are doubled: 24.7 and 25.9. When one parent has deaf relatives and the other has not, the percentages are 6.6 and 6.4; when both have, the percentages are nearly four times as great: 23.5 and 20.9. When both parents are congenitally deaf but neither has deaf relatives, the percentages are 7.1 and 4.1. When both are adventitiously deaf and both have deaf relatives, the percentages are 17.5 and 9.6. When both are congenitally deaf and one has deaf relatives, the percentages are 16.3 and 20.0; and when both have deaf relatives, the percentages are 28.4 and 30.3.