The senses and the intellect.

  • Bain, Alexander, 1818-1903.
Date:
1885
Catalogue details

Licence: Public Domain Mark

Credit: The senses and the intellect. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    countless millions of nerve cells existing in the grey substance of a single convolution of the brain. The minuteness of the fibres and vesicles of the nerve substance is not without importance, for we are to consider that each fibre carries forward its own distinct impression without affecting, or being affected by, the impressions passing along the other fibres that run side by side with it in the same bundle. In the act of perceiving the objects about us, this distinctness enables us to hold in our minds all the parts of a complicated scene, each in the proper place, without mingling or confusion ; and in the command of our muscular movements it gives the means of singling out specific muscles to be acted on while all the others are left quiescent. OF THE NERVOUS CENTRES. 5. In the collective mass made up of the brain and spinal cord, and denominated the cerebro- spinal axis or centre, the following parts stand distinct from each other, although mutually connected by bundles of nerve fibres. I. The Spinal Cord, contained in the back bone, and sending out two pairs of nerves from between every two vertebrae, one pair to each side of the body. The Cord consists of a column of white fibrous matter with a grey portion enclosed. In a cross section, the grey matter is seen to form two crescents with the horns turned outwards, and connected in the middle of their convexities by a cross band. * ' Plans in outline, showing the front, A, and the sides, B, of the spinal cord with the fissures upon it; also sections of the grey and white matter, and the roots of the spinal nerves, a, a, Anterior fissure, jo, p, Posterior fissure, b, Posterior, and c, Anterior horn of grey matter, e, Grey com- missure, r, Anterior, and s, Posterior roots of a spinal nerve.'—Quain, p. 676. Fig. 2 * A