Graphic illustrations of abortion and the diseases of menstruation / Consisting of Twelve Plates from Drawings Engraved on Stone, and Coloured by Mr. J. Perry, and Two Copper-plates from the Philosophical Transactions, Coloured by the Same Artist. the Whole Representing Forty-five Specimens of Aborted Ova and Adventitious Productions of the Uterus, With Preliminary Observations, Explanations of the Figures and Remarks, Anatomical and Physiological.

by A. B. Granville

Fig. 4. Ovulum semi-lanuginosum.

(Four weeks after menstruation.)

I look upon this as one of the most perfect specimens of mono-embryoferous Ovula at four weeks, I have seen; exhibiting as it does, not only the mossy or nutritive, but also the inner, amnionic, or secreting involucrum, with its peculiar inflected turn, forming a sacculum within which is lodged the embryo. The nutritive involucrum is separated from the middle membrane by the allantoid cavity, and the middle membrane itself stands aloof from the amnion, owing to the vesicula umbilicalis. The existence of these various elementary parts of the human Ovum in the present specimen, shews its early development, and serves to fix its age, which I consider to be of about three weeks and a half.

As gestation advances, some of those elements are obliterated, and others confounded together.