I know there was never an explanation on-screen of where McCoy's nickname "Bones" came from, and it can easily be explained as something to do with being a physician, etc. But, anyone recall any good novels/stories/fan productions which ever hinted at or gave an explanation for this particular nickname? I can't, off the top of my head, nor can I recall any fan consensus on this (unlike, say, a number of names -- Hikaru being Sulu's first name, Kirk's parents being George and Winona, etc.)