Microscopic anatomy of the lumbar enlargement of the spinal cord / by John Dean.

  • Dean, John, M.D.
Date:
1861
Catalogue details

Licence: Public Domain Mark

Credit: Microscopic anatomy of the lumbar enlargement of the spinal cord / by John Dean. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

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    THE LUMBAR ENLARGEMENT OE THE SPINAL CORD. I propose, in the following paper, to notice a few points in regard to the structure of the spinal cord, confining myself chiefly to a description of the course of the fibres forming the nerve-roots, as they pass through the white and gray substances to their final union with nerve-cells, discussing somewhat at length the relation which nerve- cells and fibres sustain in the cord. In drawing up the descriptive details of this memoir I have restricted them chiefly to the lumbar region in some of the higher vertebrates, lest any deductions I might attempt to establish should be embarrassed by the necessity of comparing observations made upon portions of the cord differing somewhat in structure. The division commonly made in the substance of the cord into gray and white matter, or into vesicular and fibrous, seems to be tenable only when we state the differ- ence between them to consist in the presence of true nerve-cells in the gray or vesic- ular, while they are absent in the white or fibrous substance. This distinction seems to me the only correct one, for I am fully satisfied that the so-called cells of the white substance, described by Stilling and others, are nothing more than cells belonging to the connective tissue, or, as sometimes occurs, true nerve-cells which have been isolated from the gray substance by the plane of section. Bidder* remarks on the situation of cells evidently connected with the cornua, that they are sometimes quite encircled by the white substance, in which rare case this substance forms but a very small partition separating them from the gray. This every observer will have noticed, and I have often in longitudinal sections found such cells quite isolated, which I should have con- sidered as belonging to the white substance, had not the section, following a slightly * Bidder and Kupffer, Untersuch. iiber die Textur d. Riickenmarks. Leipzig, 1857.