Volume 3

Manual of human and comparative histology / edited by S. Stricker ; assisted by J. Arnold [and others] ; translated by Henry Power.

New Sydenham Society.

Date:: 1870-73

Credit: Manual of human and comparative histology / edited by S. Stricker ; assisted by J. Arnold [and others] ; translated by Henry Power. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

570/608 (page 548)

$muscle cases, is nearly constant tln^oughout the whole vertebrate series. Both extremities of the prism are covered by a thin layer of fluid (muscle-case fluid). Between each two muscle cases is a basal membrane, by which the cases are separated from one enother. Each case, however, only possesses a single lateral membrane, investing it annularly, which fuses with the two terminal basal membranes. The muscle cases are arranged in the form of regular disks in the transverse direction of the spindles, which may be called muscular fibres. Each muscle compartment consists of a basal membrane, which appears in profile as a transverse line. Then in the longitudinal view of the muscle spindles there follows one half of a clear transverse band, a dark transverse band, then the half of the succeeding clear transverse band, then again the transverse line formed by the septum, and so on. The most noticeable difference in the signification which Hensen on the one hand, and Krause on the other, give to the appearances presented, is that Krause regards that as a muscle prism, and consequently as an anisotropal part, which Hensen holds to be intermediate substance, and an isotropal part. Heppner* has raised objections to the accounts given by Hensen and Krause. In his opinion, the refractile zone (muscle- case fluid of Krause, transverse disk of Hensen) is only the expression of total reflexion which occurs at the line of de- marcation between the chief and the intermediate substance. In support of his views he adduces the circumstance that the position of the refractile band, in relation to the limiting layer dividing it (median disk, Hensen—transverse line, Krause), can be altered by changing the position of the mirror, and that in certain positions of the mirror the bands may disappear al- together. He adduces also the appearances presented under polai'ised light. If the visual field be coloured by a Nicol's prism, both the refractile band and the dull disks constantly appear to be of the same colour. Both Hensen and Krause, however, maintain that only one of the two is anisotropal. So far as regards the explanation given by Krause and Hensen of the appearances first described by them, I must$