[Formation of amnion cord in a young defective human embryo (author's transl)].

A report about a human embryo of about 4 weeks of age afflicted with the formation of amnion cord with a slinglike formation. The corion sac had on its surface only a sparse cover with chorion vili. The intraembryonical vascular system was not shown except of small partial spaces in the front sector. The cause for the formation of an amnion cord is seen primarily in a faulty supply of the amniotic sac with its content. The formation of an amnion cord has been interpreted for this early phase of the embryogenesis as follows: In sufficiency of nourishment led to a dehiscence of the amnion. Mesenchym entered from the extraembryonal celom and combined itself with the lateral wall of embryo which showed because of insufficient nourishment in one area of defective epithelium. The mesenchym, which surrounded the frontal trunk part did not connect with the embryo and grew because of growth pressure into a loop with collagenous fibers. Amnionepithelecells spread only secondarily over the mesenchymloop and epithelialized it.