Mumbledy-peg was not a marbles game. It was a game played exclusively by boys, using their pocket knives. Basically, you had to perform, in sequence, a series of manouvres or tricks, of increasing difficulty, with your knife in the grass (not in the dirt, since that tended to dull the blade). Girls, of course, did not have knives. This brings up the astonishing fact, which I learned from a newspaper article recently, that marbles is still a very popular pastime in some parts (rural) of the US and there are large tournaments and -- blasphemous thought -- GIRLS TAKE PART. That was unthinkaable in my youth. The sexes each had their own activities, like jumping rope for girls, marbles & mumbledy-peg for boys, and taking part in the others' games would have been like cross-dressing.