Amnion: the inner of the two membranes enveloping the embryo.
The embryo when about to hatch throws off the egg-shell and amnion in a few seconds.
Only in the chancel were they protected by sheep's amnion stretched on frames.
The amnion contains a fluid known by the name of liquor amnii.
Both it and the stalk of the yolk-sack are enveloped by the amnion (am).
It adheres ...