The senses and the intellect / by Alexander Bain.

  • Alexander Bain
Date:
1864
Catalogue details

Licence: Public Domain Mark

Credit: The senses and the intellect / by Alexander Bain. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

    105/679 (page 73)
    ‘ The fibres, although they differ somewhat in size individually, ' have'the same average diameter in all the voluntary muscles, namely? about of an inch ; and this holds good whether the muscles be coarse or fine in their obvious texture. According to Mr Bowman : their average size is somewhat greater in the male than in the female, being in the former and in the latter or more than a fourth smaller.’—Ib. ‘ As to the structure of fibres, it has been ascertained that each i is made up of a larger number of extremely fine filaments or fibrils, 1 inclosed in a tubular sheatli.’ ‘ It would seem that the elementary ] particles of which the fibril is made up, are little masses of pellucid . substance presenting a retangular outline, and appearing dark in the ' centre.’ ‘ The length of the elementary particles is estimated by Mr. Bowman at of an inch. He finds that their size is remarkably uniform in mammalia, birds, reptiles, fishes, and insects.’—Ib. Nerves of Voluntary Muscles.—‘ The nerves of a voluntary muscle are of considerable size. Their branches pass between the fasciculi, and repeatedly unite with each other in form of a plexus, which is for the most part confined to a small part of the muscle, or muscular division in which it lies. From one or more of such 'primary plexuses nervous twigs proceed and end by finer or terminal plexuses, formed by slender bundles consisting of two or three primitive tubules each, some of them separating into single tubules.—Quain, clii. ‘ By means of the microscope these fine nervous bundles and single tubules may be observed to pass between the muscular fibres, and after a longer or shorter course, to return to the plexus. They cross the direction of the muscular fibres directly or obliquely, form- ing wide arches; and on their return they either rejoin the larger nervous bundles from which they set out, or enter into other divisions of the plexus. The nervous filaments, therefore, do not come to an end in the muscle, but form loops or strings among its fibres.’—Ib. clii. * I refrain from transcribing the description given of the involuntary muscles,—those of the heart, intestines, bronchial * The active connection between the nerves and the muscles would seem to consist in an electrical current passing from the one to the other. The numerous experiments of Du Bois Reymond and others in this subject, scarcely permit any other conclusion.