Note: Do not rely on this information. It is very old.
Urachus, a fibrous cord connecting the summit of the bladder with the anterior abdominal wall.
“Not a drop of rain falls in the sandy desert or on the barren rock, however useless it may seem to be, that is not seen to be of value by God, and that is not designated to accomplish some important purpose there.”
–Albert Barnes, Notes, Job 38:26