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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    to all media, conform to all circumstances, or vary and modify its actions in a thousand ways ; yet it is capable of modification within certain limits, when subjected to strong and lasting influences. Two causes chiefly produce these variations : external conditions and dom'estication. Climate, soil, food; the dangers which habitually surround the animal, and the impressions it receives, modify its organism and consequently its instincts. The action of man is still more powerful on the animal than that of Nature : by training, man fashions and bends it to his needs or his wishes. It is not for us to inquire here how these acquired or modified instincts are produced. We have only to ask whether they are hereditary. Experience answers in the affirmative; many facts show that acquired instincts, as well as those which are natural, are transmitted by heredity. Such are the following :— G. Leroy observes that in districts where a sharp war is waged against the fox, the cubs, on first coming out of their earths, and before they can have acquired any experience, are more cautious, crafty, and suspicious than are old foxes in places where no attempt is made to trap them. This he explains by the hypothesis of a language among animals. F. Cuvier has furnished the solution of the enigma by referring the fact to the heredity of. modifications which are acquired by instinct. There is no doubt that the instinct of fear is acquired in many wild animals, and transmitted to their - descendants. Knight, who for sixty years devoted himself to systematic observation of this class of facts, says that during that time the habits of the English woodcock under- went great changes, and that its fear of man was considerably increased by its transmission through several generations. The same author discovered similar changes of habit, even in bees. Darwin has established the fact that animals living in desert islands gradually acquire a fear of man, in proportion as they become acquainted with our methods of destroying them. He says that in England large birds are much more shy than small ones, and this, no doubt, because they are much more persecuted by man. The proof that this is the reason of the difference is found in the fact that in uninhabited islands large birds are not any more timid than small ones.^ ^ Origin of Species, p. 260. Fifth Edition, 1869. Lucas, ii. 482.