The fundus oculi with an ophthalmascopic atlas, illustrating its physiological and pathological conditions / By W. Adams Frost.

  • Frost, W. Adams (William Adams), 1853-1935.
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: The fundus oculi with an ophthalmascopic atlas, illustrating its physiological and pathological conditions / By W. Adams Frost. 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.

    47/449 (page 23)
    6. The inner nuclear layer resembles the nuclear portion of the external nuclear layer (4). A connection has been demonstrated between the nuclei of this inner nuclear layer and the nerve cells in the next layer (8); concerning its connection with the more external layers there is much uncertainty. 8. The layer of ganglionic nerve cells consists of large multipolar cells from each of which one process passes into the layer of nerve fibres. From the other surface project a number of processes, varying from one to four, most of which appear to be lost in the adjacent inner nuclear layer; a few, however, can be traced as far as the external nuclear layer. 9. The layer of nerve fibres is thickest near the disc, and stops short before reaching the ora serrata. It consists of fibres which are continuous with those of the optic nerve, but which differ from them in having lost their outer coating of the white matter of Schwann, or medullary sheath. They are, in consequence, thin and transparent. The larger vessels of the retina lie in this layer. 10. The internal limiting membrane is a thin not conspicuous membrane, which is usually described as being formed by the expanded extremities of the fibres of Muller. The fibres of Muller, to which reference has just been made, are not shown in the figure, they are straight filaments, which pass vertically through the intervening layers from the external to the internal limiting membrane. They have usually been con- sidered as forming part of the connective tissue framework of the retina. Borysiekiewicz1 has, however, shown that they are directly continuous with the bases of the cones. And if this is really the case, it is probable they constitute nerve organs of great importance. The structure of the retina is somewhat modified at the macula. This will be considered later on. The vessels of the retina are branches of the central artery and vein. Those that are of sufficient size to be visible with the 1 Lnc. cit.