Thread:Monet47/@comment-5560696-20121009014711/@comment-4242472-20121009180516

Reinforcement, made of bone. The "empty internal cavity" concept is what most people might think when they hear "hollow bones" since ours are either sollid or filled with squishy marrow.

And I said 'could be', which means they aren't always a hinderance and i believe a single large cavity is probably the least efficient support design.