The origin and development of the umbilical cord, and its relation to the amnion / by James Foulis, M.D.

  • Foulis, James.
Date:
[1900]
Catalogue details

Licence: In copyright

Credit: The origin and development of the umbilical cord, and its relation to the amnion / by James Foulis, M.D. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    seen passing into the body of the embryo through the coelomic opening of the umbilical foramen. The Bauchstiel, L, was a well-marked string-like structure. It was cut transversely across close to the rump end of the embryo ; and then it was possible to see in the centre of the cut surface, as indicated by the letter M, the well-marked tubular orifice of the allantoic vesicle. The letter L points to the situation of the allantoic tube itself as it lies enveloped in a thick mesoblastic covering, between the line of the large blood vessels, veins and arteries, which go out towards the chorion, as indicated by the letters K K. The amnion membrane somewhat distended by fluid could be seen at the sides of the embryo, H, and then, after embracing the rump end, it turned sharply upwards to be attached to the under surface of the Bauchstiel at its root. Between the letters H and K, this part of the amnion passing upwards to be attached to the under surface of the Bauchstiel at its root is well seen. In Plate ix. we have very carefully represented the appear- ances seen in the case of a young sheep embryo, as it lies completely encased in the amnion sac which is everywhere distended with fluid. The letter A points to the head. Below the head the heart and liver are seen. The letter B points to the true umbilical cord and to the large umbilical vein in its substance. The letter C points to the shrivelled up yolk sac which appears to pierce the umbilical cord at its front part. The yolk sac now lies quite outside the sac of the amnion. The letter N points to that part of the ventral string which is now entirely outside the amnion sac after the umbilical foramen has completely closed in around the vitelline duct of the yolk sac. The letter M points to the hind limb and tail within the amnion ; and the letter O points to the general amnion sac filled with fluid to distension, and now attached to the embryo only at the distal end of the true umbilical cord at a pomt where the vitelline duct appears to pierce and enter the front part of the umbilical cord. Looking at the figures in Plates i., ii., vii., vni., we may now ask, how is' the Bauchstiel, or ventral string, whose origm, development and relations we have described, converted mto the young umbilical cord, B, which is so well seen m the embryo before us, in Plate ix ?