Lectures on the development of the gravid uterus / by William O. Priestley.
- Priestley, William Overend, 1829-1900.
- Date:
- 1860
Licence: Public Domain Mark
Credit: Lectures on the development of the gravid uterus / by William O. Priestley. Source: Wellcome Collection.
Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.
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![it which is copied from M. Jacquemier, the relation of this vesicle to the foetus and membranes will be more easily comprehended. Fl«. 12. niagram of the embryonic vesicles, from M. Jacquemier. 1. Cavity of amnion ; 2. Umbilical vesicle; 3. Allantois bearing on each side, 6 and 6, the umbilical vessels to the chorion; 4. Ventral surface of embryo ; 7. Its dorsal surface. The umbilical vesicle, or, as it is sometimes called, the vesicula alba, is also contained in the interspace between the chorion and amnion. It is a much more distinct structure than the allantois, and retains its pouch-like form for a longer period. For this reason it has been more generally recognised and described by investigators in embryology than the allantois, although in the human species at least, it is apparently not so important in function as the latter. It was observed by Albums, Wrisberg, and the Hunters, and the later researches of Muller, Wagner, Coste, Allen Thomson, &c., leave no doubt that it exists as a normal and constant appendage to the early embryo. The vesicle is largest during the first weeks of development, and communicates freely, by means of a wide duct, with the intestinal canal of the foetus at the situation of the umbilicus. Observations made on the develop- ment of the chick, leave no doubt that it is identical with the yolk- bag, which is so prominent a structure in the egg of birds, and which furnishes a supply of nourishment for the formation and growth of the new being. The sidieroidal hmnan ovulum, when first lodged in the uterus, represents not inaptly a hen’s egg; its external envclo]ic, or zona pcllucida, with the albuminous layers](https://iiif.wellcomecollection.org/image/b22334452_0050.jp2/full/800%2C/0/default.jpg)
