The essentials of histology, descriptive and practical, for the use of students.

  • Sharpey-Schäfer, E. A. (Edward Albert), Sir, 1850-1935.
Date:
1902
Catalogue details

Licence: In copyright

Credit: The essentials of histology, descriptive and practical, for the use of students. 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.

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    The macula lutea (yellow spot), with its central fovea, is tlie part of the retina which is immediately concerned in direct vision. It is characterised firstly by its greater thickness (except at the middle of the fovea), secondly by the large number of its ganglion-cells, which are rounded or conical, and thirdly by the large number of cones it contains as compared with the rods. In the central fovea itself (fig. 616) there are no rods, and the cones are very long and slender, measuring not more than •2/x in diameter; all the other layers Fici. (jlO.—Section Tiinouciii thk central i-akt of tuk fovka ckntkai.i:>. ^f^. (From a preparation by C. H. Golding-Bird.) M, bases of Miilleriaii fibres; c.b., iiuelei of inner granules (liipolars): c.»i., cone-tibre nuclei; c, cones. become gradually thinned down almost to complete disappearance, so that the middle of the central fovea is the thinnest part of the retina. Since there are few rods, the outer granule laj-er loses in great measure its appearance of being composed of closely packed nuclei, and the cone-fibres are very distinct, forming the ao-caWGd Jibroniil(j;/er. The direction of these fibres is for the most part very oblique in tliis part of the retina. The pigmentary layer is thickened over the fovea, and there is also