The diseases of the will / by Th. Ribot.

  • Ribot, Th. (Théodule), 1839-1916.
Date:
1903
Catalogue details

Licence: In copyright

Credit: The diseases of the will / by Th. Ribot. Source: Wellcome Collection.

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    blood move ahead little by little by the aid of the pro- cesses which they emit. These facts, which may be found described in abundance in special works, show us that motility appears long before the muscles and the nervous system, even in their most rudimentary form. We need not follow the evolution of these two in- struments of improvement through the animal series. Let us merely note that the researches on the localisa- tion of the motor centres, so important in the mecha- nism of the will, have led some savants to study the state of these centres in the newly born. “ This in- vestigation, very carefully made by Soltmann, in 1875, has furnished the following results. In rabbits and dogs there exists immediately after birth no point in the cerebral cortex the electric irritation of which is capable of producing movement. It is only on the tenth day that the centres for the anterior members develop. On the thirteenth day the centres for the posterior members appear. On the sixteenth, these centres are already quite distinct from each other and from those of the face. One conclusion to be drawn from these results is, that the absence of volun- tary motor direction coincides with the absence of the appropriate organs, and that, in measure as the ani- mal becomes more master of its movements, the cere- bral centres in which the elaboration of will takes place acquire a more manifest independence.* Flechsig and Parrot have studied the development of the encephalon in the foetus and the infant. From the researches of the latter *j‘ it appears that, if one fol- * Dictionnaire encyclopidique des sciences ntidicales, FranQois-Franck, ar- ticle “Nerveux,” p. 585. t Archives de physiologic, 1879, pp. 505-520.