Growth - side of hammer

[RaymondL]

This picture isn't mine as I couldn't take a better picture than this, but is this new hammer head growth? I thought hammer grows mainly by splitting of existing head, and not sprouting new ones as such on its stem.

 

[mangus]

Yes, that is a new head growing. Hammers that are from Indonesia split in both ways while hammers from Australia only split the existing heads.