A manual of human microscopic anatomy / by A. Kölliker.

  • Kölliker, Albert, 1817-1905.
Date:
1860
Catalogue details

Licence: Public Domain Mark

Credit: A manual of human microscopic anatomy / by A. Kölliker. Source: Wellcome Collection.

    589/684 (page 569)
    nevertheless, the essential points of the course of the fibres just described remain completely the same, seeing that in these more complex stars the rays of the anterior and posterior aspects do not correspond, and that no fibre goes from one pole to the other. In the stars, the substance of the lens is not formed of tubes as else- where, but consists of a material which is in part finely granular, in part homogeneous; and, therefore, it happens that, as the stars pass through all the laminse, there exist three or more perpendicular, non-fibrillated planes (central planes, Boivma?i) in each half of the lens. The tubes of the lens become broader in the neighbourhood of the stars, but do not here coalesce with each other, for they terminate in clavate and fusiform enlargements of most diverse form, which often appear polygonal when seen from the surface (see my Micr. Anat., ii. 2, fig. 416). The fibres of the lens are sometimes finely striated longitudinally, and fur- nished with delicate, transverse lines, which cannot be referred either to fibres or to cells.—The superficial fibres of the lens are each provided, in the region of the equator of the lens, with a single, beautiful nucleus, which, the further we proceed inwards, becomes smaller and smaller, and at last disappears. Thomas found, on sections of dried lenses, two or three systems of concentric lines, which Czermak has recently explained in a way reconcileable with the structure of the lens. § 228. The vitreous body {corpus vitreum) completely fills the space between the lens and the retina, lying only loosely upon the proper retina, except at the place of entrance of the optic nerve, where the connection is somewhat more intimate; but, on the other hand, being very firmly connected with the corona ciliaris and the lens itself. The membrane enveloping the vitreous body (the memhrana hyaloidea) occurs behind the ora serrata in the form of an extremely fine and delicate, clear pellicle, scarcely per- ceptible under the microscope; it is more readily visible at the bottom of the eye-ball, where it measures 0 004 of a millimetre (o-oo2''')> according to //. Müller. In front of the ora serrata, the hyaloid membrane becomes somewhat firmer, and proceeds, under the name pars ciliaris hyaloidece s. zonula Zlnnii (lig. suspmsorium lentis, Boicman), to the border of the lens, in order to coalesce with the capsule of it. During this course, it divides into an anterior and a posterior lamella, the latter of which coalesces with the capsule of the lens somewhat behind its border, but continues to be recognisable {Ao4t, H. 3Iüller) throughout the whole extent of the circular fossa of the vitreous body. The anterior lamella, connected with the ciliary processes, forms the zonula, in the more