My sisters boy and his wife recently had a baby boy.(David ) He was born with a Caul over his face and being from Liverpool,the nurses must have been aware of the significance and carefully removed it and preserved it in a small jar.
This was then placed on the table next to her bed in the maternity ward.Imagine her surprise,when she woke up after a much needed sleep to find that somebody had stolen the jar !! 18th/19th Century sailors would pay good money for them as protection against drowning.
So the Idea still lives in seafaring cities it seems.........