Volume 2

Manual of descriptive and pathological anatomy ... / Translated from the German into French, with additions and notes, by A.J.L. Jourdan ... and G. Breschet ... Translated from the French, with notes, by A.S. Doane, and others.

  • Meckel, J. F. (Johann Friedrich), 1781-1833
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: Manual of descriptive and pathological anatomy ... / Translated from the German into French, with additions and notes, by A.J.L. Jourdan ... and G. Breschet ... Translated from the French, with notes, by A.S. Doane, and others. Source: Wellcome Collection.

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    the other, It presents a slight prominence in its centre, and is separated hy a slightly perceptible contraction from the hemispheres which it uiiites. The central pari or the pyramid (pyramis, Malacarne) is next to this prominence, and is separated from it by a very deep fissure. This central part projects in every direction much more than the posterior, and is attached, by much norrower and lower lateral parts, to the posterior half of the inferior external lobe, and to the inferior internal lobe. Next to the pyramid, from which it is separated by a deep groove, comes a narrow part which is easily dividedinto severallobes situated one over another, and which generally is not perfectly symmetricaL being turned first to the right, and then to the left. This part also projects still more, in proportion to its breadth, and is continuous with the amygdalae by a narrow and deeply situated meduUary band, Finally, we next observe the anterior and smallest part, called the nodale (nodulus, Malacarne), which is continuous on each side, with the posterior valve. Thus, the central portion of the cerebellum, considered as awhole, is so curved, first from before backward, then from below upward, next from above downward and from behind forward, that the two extremities of the vermiform process, which proceed to ward each other, almost touch, and are separated only by the narrow face of the summit of the fourth ventricle. II. TEXTURE. § 1745. The grey substance surrounds all parts of the cerebellum ex- cept its lower face, which corresponds to the fourth ventricle; this is covered with medullary substance. The latter is continuous in the three prolongations of the cerebellum, anteriorly with the tubercula quadrigemina, posteriorly with the medulla oblongata, below and on the side, with the annular protuberance and, extends within this Organ in ramifications, the collection of which is termed the arbor vit(g ; to this we may be convinced by vertical incisions. The medullary trunks follow a more or less curved direction to near the circumference of the cerebellum, and give oflf, in this course, a greater or less number of branches, which arise from their convex edge. A thin layer of yellow substance, covered by a thick layer of grey substance, e.xists on the surface of each medullary branch. This arrangement causes the lamellar structure of the cerebellum, since each layer encloses a layer of medullary substance, and each of the laminaa into which the priucipal layers divide always corresponds to a medullary substance. The middle and lower part of the cerebellum presents this arrange- ment most distinctly. We find in this place seven medullary layers,