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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    lined with hypoblastic cells. The mesoblastic tissue around this allantoic bladder is very vascular, and in it are seen numerous arteries and veins. Let us now consider a little more carefully the origin and development of The Bauchstiel, Abdominal Stalk or Ventral String, AND its relation TO THE SOMATOPLEURE FOLDS AND Amnion One hundred and thirty-five photographs of sections through this young embryo were placed in. their proper relation to each other, and fixed on a large piece of cardboard for study. The sections examined passed, first of all, through the yolk sac and its attachment to the primitive intestine, then through the middle part of the body, then through the lumbar region, and lastly through the Bauchstiel and rump end of the embryo. The following conclusions were drawn from such a study. At an earlier stage of development than this embryo presents, there must have been a folding over of the three primary layers of the embryo to produce the head fold by which the fore gut was included in the head region as a blind tube. The cephalic somatopleure fold can be traced in this region bending upwards and backwards over the head of the embryo to be continuous with the general amnion sac. This cephalic fold of somatopleure starts from the cephalic end of the umbilical foramen. The two lateral somatopleure folds can be traced bending back and then turning round the dorsal surface of the embryo as the amnion membrane. They border the lateral parts of the umbilical foramen. At the caudal end of the embryo there must also have been a folding over of the primary layers to produce the tail fold which encloses the blind hind gut; and in the sections it is easy to follow the bending back of the caudal somatopleure fold which, as a thick layer, turns backwards and downwards to embrace the rump end of the embryo produced by the tail fold. All these somatopleure folds, the cephalic, lateral, and caudal folds, are directly continu- ous with each other round the margin of the large umbilical foramen ; and while the cephalic fold turns upwards and back- wards to embrace the head, the somatopleure folds in all other parts turn downwards and backwards to embrace the dorsal surface and rump end of the embryo in one continuous sheet.