There is much to be learned, also, from a little trick that a Japanese master of jiu-jitsu would be likely to employ if annoyed by too much pushing from the rear in an American crowd. In Japanese crowds, no matter how densely packed the people may be, no one intentionally shoves. But in the United States, the bothered Japanese would turn slightly in order to make sure of the man who had annoyed him, and would then make a sharp jab with the point of his elbow in the boor's solar plexus. There would be a gasping "Ouch!" from the boor, whereupon the master ol jiu-jitsu would turn with the smiling politeness that never deserts the Japanese:
"I beg your pardon, but I had no idea that my turning so suddenly would put you to such inconvenience."
And there would be nothing logical for the boor to do save to accept the promptly proffered apology—and do his best to preserve as great a distance as possible between himself and the master of jiu-jitsu. In Japan the trick is employed to prevent an attack from the rear when the danger of one is realised. The blow
