SKULL
'(<a href="http://www.j-archive.com/media/2008-10-17_J_30.jpg" target="_blank">Jon of the Clue Crew points to an anatomical diagram on the monitor.</a>)  Allowing molding of the head during birth, soft spots on a baby's skull, also known as these, are surrounded by bones that fuse & harden by 18 months'
fontanels