The hand : its mechanism and vital endowments, as evincing design, and illustrating the power, wisdom, and goodness of God / by Sir Charles Bell.

  • Bell, Charles, Sir, 1774-1842
Date:
1872
Catalogue details

Licence: Public Domain Mark

Credit: The hand : its mechanism and vital endowments, as evincing design, and illustrating the power, wisdom, and goodness of God / by Sir Charles Bell. Source: Wellcome Collection.

    32/310
    community of office is observed : each organ becomes disembar- rassed of the duties of the others, and performs its own particu- lar function alone. At length, when the animal organisation has reached its highest point of development in Man, we find Locomotion executed exclusively by its appropriate members— the Lower Extremities: Prehension executed exclusively by its appropriate members—the Upper Extremities: and Mastication by its appropriate instruments—Jaws and Teeth. And here it may be observed, that, when the Lower Extremi- ties, by their perfect construction as implements of locomotion, have emancipated the Upper Extremities from sharing in pro- gression, so that the Hand and Arm are independent, and available for all acts of prehension, the Jaws and Teeth cease to be employed for seizing and holding. The mouth is exempt from performing any other duty but that of Mastication. Con- sequently, the bones of the face, jaws, and teeth admit of being reduced in dimensions : and the cavity of the mouth adapted, in size and form, to be an important part of the organ of Voice and Speech, in relation to man’s highest endowment— his Mind. Such being the association of organs necessary for the con- struction of an Animal, viewed in the abstract, the question next arises—How is the mechanism to be animated; or, what must be the combined properties of a Nervous System, de- signed to meet the wants of the organism ? By following that inquiry, we may be led to ascertain what is the most element- ary form of a System of Nerves. In the simplest view that can be taken of a nervous system, we must suppose the existence, in some part of it, of a central organ, corresponding to the Brain in the highest animals; an organ from which motor power may be transmitted to the muscles, and to which one or more senses may be conveyed from the surface. It is also reasonable to assume, however difficult it may be to prove the fact anatomically, that in the elementary brain the particular structure which initiates motor influence will be different from that which receives impres- sions from the senses. With the doubly-constituted organ thus introduced, it must be supposed that nerves will be provided as media of commu- nication-one set for giving Motion, and the other for giving