On the anatomy of the fovea centralis of the human retina / by J. W. Hulke.

  • Hulke, J. W.
Date:
[1867]
Catalogue details

Licence: Public Domain Mark

Credit: On the anatomy of the fovea centralis of the human retina / by J. W. Hulke. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    6/10 (page 114)
    nations of the optic nerve-fibres; and at their junction with the outer segment the con version of light iiito nerve-force may take place. 4. The outer granules being the nuclei of the inner cone- and rod-segments, probably maintam the integrity of these as living tissues, and are not directly concerned in their specific functions as organs of perception. 5. The primitive bacillary fibres are the link by which the cones and rods communicate through the inner granules and ganglion-cells with the optic nerve-fibres. 6. The smaller inner granules are nuclei of the oblique bacillary fibres in the inner granule-layer; or they may be small bipolar ganglion-cells, and act specifically on the forces transmitted through the oblique fibres from the cones and rods. The larger inner granules not being distinguishable by any definite structural characters from the smaller cells of the ganglionic layer, may agree with these latter cells in function. 7. Since the ganglion-cells (of the ganglionic layer) are fewer than the inner granules, and much fewer than the cones and rods, and since it is probable that these latter com- municate with the optic nerve-fibres only through the ganglion-cells, it follows that one ganglion-cell probably is in correspondence with more than one inner granule and with several cones and rods. From this it is not an improbable conjecture that the cones and rods are disposed in groups*, each of which is represented by one or more ganglion- cells, the function of which is to connect or coordinate the individual action of the separate bacillary elements in their groups in a manner analogous to that attributed to the ganglion-cells of the spinal cord by V. der Kolk. 8. There is a close general resemblance between the human fovea and that of the chameleon f. Desckiption of the Plate. PLATE VII. Fig. 1. A vertical section through the centre of the fovea centralis in the vertical meri- ridian, extending about halfway towards the periphery of the macula lutea, X24U. 1. Bacillary layer. ■2. Outer granule-layer. 3. Cone-fibre plexus. 4. A granular band between the latter and the inner granule-layer. 5. Inner granule-layer. 6. Granular layer. 7. Ganglionic layer. a. Centre of fovea; fj, membrana limitans externa; c, membrana limitans interna; d, section of a blood-vessel. * I have an impression that I have seen this in a Gcnium author, hut have not heon able to find the passage again. t H. MtLLEE, Uebcr das Augc des Chamiilcons, Wurzb. Naturw. Zchr. Ld. iii. S. 3G.