Human embryology / by Charles Sedgwick Minot.

  • Charles Sedgwick Minot
Date:
1892
Catalogue details

Licence: Public Domain Mark

Credit: Human embryology / by Charles Sedgwick Minot. Source: Wellcome Collection.

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    the traces of cellular structure in the reflexa are still more vague and the fibrin is more developed. The membrane is much thinner than at two months; the thickness is about two-thirds of what it was. In the fresh specimen the membrane appeared much more transpar- ent than before. In all the parts examined I found leucocytes pres- ent, and in the region of the reflexa near the placenta they are very numerous and conspicuous; it is natural to conclude that they are concerned in the resorption of the degenerated tissue. In a section not far from the base of the reflexa the throe layers are distinct as at two months, there being a thicker inner and a thinner outer fibrin layer, while between them is a stratum in which remains of cells are seen; occasionally is an appearance which suggests a sur- viving decidual cell, and nearer the placenta the phantoms of cells become distinctly cells, and true decidual cells can be made out. The inner fibrin layer is much denser and its meshes smaller than in the two months specimen, the trabeculse of fibrin having become thicker during the month elapsed. Those who conceive that there is a fusion between the reflexa and vera, are forced to seek for traces of the former membrane next the chorion. They may assume either that the epithelioid layer (cho- rionic ectoderm) is the remnant of the decidua, which forces them to leave the fate of the chorionic epithelium unexplained, or that the upper stratum of the decidua is the reflexa which is fused with and acquired the same structure as the underlying vera. If my obser- vations on the degeneration of the reflexa are correct, and corre- spond, as there is sufficient ground to believe they do, to normal con- ditions, then both assumptions as to the persistence of the reflexa involve the further and very improbable assumption that the degen- erated tissue is removed and replaced by fully organized cellular decidual tissue. It is obviously more in accordance with our knowl- edge of degenerative changes to assume that the hyaline metamor- phosis is necrotic and is succeeded by the disintegration and removal -■ i I Fig. Sectiou of liumau decidua reflexa at two uioutiis.
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