UR modern American underworld differs little in spirit from that of Greene and Dekker, of Cervantes and Aleman. It is true that the technique of rogue and officer have changed; Dekker's glossary of "canting language"-complete though it was, for Dekker spent enough of his life in jail to be thoroughly conversant with his material-has given way to a succession of argots in the latest of which, so far as I can determine, not a single one of his words has survived; the social status of the criminal (and of the accused criminal) has been remarkably altered; politics, prohibition, and the general decay of so-called morality are tending to efface any sharp line which may have existed between criminality and respectability. But despite these superficial changes, the forces which mold the language of the underworld remain much the same from one age to another.