Heredity : a psychological study of its phenomena, laws, causes and consequences / from the French of Th. Ribot.

  • Ribot, Th. (Théodule), 1839-1916.
Date:
1875
Catalogue details

Licence: Public Domain Mark

Credit: Heredity : a psychological study of its phenomena, laws, causes and consequences / from the French of Th. Ribot. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    who were insensible to all sounds above and below the diatonic scale. To be congenitally deaf and dumb exerts a well-known and unfortunate influence on the development of the intellect, for which the only remedy is found in the use of artificial signs. If this infirmity is transmissible, heredity may be said to penetrate into the very essence of intellect. But this form of heredity has been disputed. Dr. Meniere, in a special work on this question, while admitting that in a certain number of instances the direct and immediate heredity of deaf-muteness has been established, says :—* Never- theless, these facts must be held to constitute a rare exception; habitually deaf-mutes married to deaf-mutes beget children who hear and speak. This is, of course, still more the case where the marriage is a mixed one, that is, where only one of the couple is deaf and dumb—though even in this case there are well-attested cases of heredity.' ^ Darwin also says :—' When a male or a female deaf-mute marries a sound person, their children are most rarely affected ; in Ireland, out of 203 children thus produced only one was mute. Even when both parents have been deaf- mutes, as in the case of forty-one marriages in the United States, and of six in Ireland, only two deaf and dumb children were produced.' ^ We would remark that the returns of the Deaf and Dumb Institution of London, from its foundation to the present time, are conclusive in favour of heredity. Among 148 pupils in that institution at one time, there was one in whose family were five deaf-mutes ; another in whose family were four. In the families of II of the pupils there were three each, and in the families of 19, two each. It is quite possible that, in the case under consideration, the law of heredity is not so much at fault as is commonly supposed. The deaf-muteness of ascendants may, in their descendants, be transformed into an infirmity of some other description, such as hardness of hearing, obtuseness of the mental faculties, or 1 Rccherches stir VOrigine de la Surdi-Mutiti, par le Docteur Meniere. - Variation, etc., \\ p. 22.