The laws and mechanics of circulation, with the principle involved in animal movement . Manual of Histology, by Prof. S. Strieker, of Vienna, Austria, in co-operation with Th. Meynert, F. von Recklinghausen, MaxSchultze, others. English translation. Art. The Organ of Vision. II. TunicaVasculosa, by Prof. A. Iwanhoff, p. 856. DUALISM DEMONSTRATED. 477 isolated bundles, after they have passed the boundary of thesphincter, unite to form a continuous layer, which spreadsover the entire posterior surface of the iris; all its fibres lieregularly parallel to one another, and all are arra
The laws and mechanics of circulation, with the principle involved in animal movement . Manual of Histology, by Prof. S. Strieker, of Vienna, Austria, in co-operation with Th. Meynert, F. von Recklinghausen, MaxSchultze, others. English translation. Art. The Organ of Vision. II. TunicaVasculosa, by Prof. A. Iwanhoff, p. 856. DUALISM DEMONSTRATED. 477 isolated bundles, after they have passed the boundary of thesphincter, unite to form a continuous layer, which spreadsover the entire posterior surface of the iris; all its fibres lieregularly parallel to one another, and all are arranged in linesradiating from the pupillary to the ciliary margin. . The dilator pupillse (Fig. 198, b) is developed from the bundlesof the sphincter as an uninterrupted continuation of thesame. At the point of insertion of the radiating fibres intothe ciliary muscles (Fig. 199, b, c) they bend suddenly uponthemselves and return to the pupillary or circular muscle,some of the loops larger than others and lying in close con-tact with the ciliary muscles, others bending higher up the. Fig. 198.—Segment of the Iris, viewed from the surface.— Jcropheef. a, Sphincter ; bt dilator. central portions in contact only (c, c), forming themselves intotwo layers (a, a). Italics are added. From this it transpiresthat the sphincter is the chief muscle in the iris, while theradiating fibres serve for assisting the action simply. Indeed,,the eminent author in the same connection uses the following-forcible language: The literature on the dilator pupillse(radiating fibres) leads us unwillingly to the belief that untilthe time of Henle the existence of this muscle was pre-supposed on the ground of absolute physiological necessity,rather than actually demonstrated, to the preva-lent belief that muscles cannot expand, consequently thatthere must be opposing muscles for pulling the sphinctersinto extension, but which we positively know to be , more than this, one portion of
Size: 1968px × 1270px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookde, booksubjectblood, booksubjectrespiration
