On inflammation / by G. Thin.

  • Thin, George.
Date:
[between 1870 and 1879?]
Catalogue details

Licence: Public Domain Mark

Credit: On inflammation / by G. Thin. Source: Wellcome Collection.

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    their way into the clefts, and, being drawn into the narrowing channel, they are seen at some parts of it as long narrow bodies. On careful examination, it can be sometimes seen that even at the narrowest parts the superficial epithelium does not bridge the cleft, but dips into it over each edge. The clefts are wider nearer the limbus, and run obliquely into the substance of the cornea, occasionally diverging as they approach its centre. When once seen, they need never afterwards be confounded with the nerves of the cornea. They are more easily recognised in inflamed preparations. These clefts indicate a further arrangement of the fibrillary substance into tracts or compartments, which, if the phraseology of “ bundles ” is to be adhered to, might be designated tertiary bundles. Horizontal layers of cornea substance, thicker than the lamella} seen under the microscope in a vertical section, may be detached from a cornea which has been for some days in weak acetic acid. Those, I believe, have a relation to layers which actually exist, because in the same animals the relative number of lamellae so obtainable is approximatively the same, and because, as I shall subsequently show, they correspond to continuous layers of flat cells in the substance of the cornea, which, we are justified by all analogy in assuming, cover free surfaces. When a cornea is placed 15 to 25 minutes in solution of chloride of gold, and is then allowed to remain exposed to a bright light for several days in distilled water, made faintly sour by adding a few drops of acetic acid, there will usually be seen interspersed through its substance large nuclei, surrounded by a dark purple granular deposit, which is continued in straight projections of varying breadth in all directions, their anastomosis forming a network. This appearance is believed by many histologists1 to coincide with a system of branched anastomosing cells, the dark purple deposit representing the cell and its processes. The constant presence of a nucleus in the centre of the mass undoubtedly ren¬ ders the interpretation a plausible one. But it is nothing better than a hypothesis. If any one chooses to say that the presence of a nucleus in the central points of a network which varies exceed¬ ingly even in animals of the same species, is no proof that the net¬ work stands in the relation of a cell to the nucleus, the objection is unanswerable. All that the gold preparations have shown is, that the constancy with which the metallic deposit has taken place in the same general form indicates a structural peculiarity 1 See, for example, Rollett, Strieker’s Handbook p. 1101 (German edition).