. The science and art of midwifery . us luteum.—The migration of the ovum.—Fecundation.—Changes taking place in the ovum subsequent to fecundation.—Nourishment ofthe embryo.—The allantois and chorion.—The deciduse.—The placenta; its de-velopment and structure.—Formation of the umbilical cord.—The amnioticfluid. The physiology of theand discharge from the ovof subsequent changes bywhich the simple structureof the germ becomes con-verted into a complex or-ganism presenting the spe-cific characteristic of theparent. The following accountof the history of the ovumis derived in great measurefrom Wa
. The science and art of midwifery . us luteum.—The migration of the ovum.—Fecundation.—Changes taking place in the ovum subsequent to fecundation.—Nourishment ofthe embryo.—The allantois and chorion.—The deciduse.—The placenta; its de-velopment and structure.—Formation of the umbilical cord.—The amnioticfluid. The physiology of theand discharge from the ovof subsequent changes bywhich the simple structureof the germ becomes con-verted into a complex or-ganism presenting the spe-cific characteristic of theparent. The following accountof the history of the ovumis derived in great measurefrom Waldeyer.* The Graafian les axi) the Ovum.—In the embryo of the chick,by the fourth day of incu-bation, the Wolffian bodyis covered by cylindricalepithelium, contrastingsharply with the flattenedcells of the after, a thickeningof the epithelium becomesnoticeable on the inner side,and forms the earliest trace ovum comprises its genesis, development,ary, its fecundation, and the entire series. Fig. 28.—Section of Wolffian body, with rudimentaryovary (embryo f chick, fourth day of incubation).WK, Wolffian body; //. section t Wolffian duct;a. a. thickened epithelium ; :. dud of BluMler : stage in development of ovary; 0, . primor-dial ova; r», mesentery ; /.. lateral wall of abdomen.(Waldeyer. I * Eierstock and Nebeneierstock, Strickers Bandbuch der Lehre von den Gewe-ben, Leipsic, ls?l ; Eierstock and Ei, Leipsic, 1870. ar, PHYSIOLOGY OF THE OVUM. of the ovary. Next, a small rounded elevation, rich in cells, and derivedfrom the interstitial tissue of the Wolffian body, makes its appearanceunderneath the thickened epithelium. The epithelium is destined toform the Graafian follicles and ova; the proliferated connective tissuefurnishes the vascular stroma of the ovary. Between the fourth andfifth day certain cells already indicate their destiny as future ova, bytheir size, their rounded shape, and large nuclei. The further develop
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Keywords: ., bookcentury1800, bookdec, booksubjectobstetrics, booksubjectwomen