Playwrights and theater-mined readers no longer need shift their ground nor fear their partial ignorance when the long-vanished Commedia dell'Arte is up for cafe espresso discussion. Professor Allardyce Nicoll has definitively spiked that butterfly against the bookcase for all time. The exact nature of the original form and all its permutations during two hundred years of life throughout Europe are displayed and examined down to the last Italian thumbprint on these splendid wings. Professor Nicoll hangs the story of the art form upon the character Harlequin and his inner indestructibility despite costume fashions and change of theatrical methods. Harlequin is a servant with the mind of a fly, who can never think more than one, very simple thought at a time, and can't retain even that longer than a few seconds, so that his stage activity constantly shifts and develops in an absurdity which becomes its own logic. He gets things done by not getting them done. The triumphant satisfaction he derives from this often enough becomes reversed to utter despair when his master discovers his servant's error. The enormous detail Professor Nicoll invests his work with often enough reverses his triumph also. The reader suspects, as windblown and pedantic comparisons between Harlequin and Hamlet are made, that the author's ""ho-ho!"" could barely make it from the front bench to the stage.