Joseph Petrosino, the able and fearless officer of New York police who was murdered in Palermo while in the service of the country of his adoption, was, while he lived, our greatest guaranty of protection against the Italian criminal. But Petrosino is gone. The fear of him no longer will deter Italian ex-convicts from seeking asylum in the United States. He once told the writer that there were five thousand Italian ex-convicts in New York City alone, of whom he knew a large proportion by sight and name.* Signor Ferrero, the noted historian, is reported to have stated, on his recent visit to America, that there were thirty thousand Italian criminals in New York City. Whatever their actual number, there are quite enough at all events. *Petrosino is a national hero in Italy, where he was known as "Il Sherlock Holmes d'Italia"--"the Italian Sherlock Holmes." Many novels in which he figures as the central character have a wide circulation there. By far the greater portion of these criminals, whether ex-convicts or novices, are the products or byproducts of the influence of the two great secret societies of southern Italy. These societies and the unorganized criminal propensity and atmosphere which they generate, are known as the "Mala Vita." The Mafia, a purely Sicilian product, exerts a much more obvious influence in America than the Camorra, since the Mafia is powerful all over Sicily, while the Camorra is practically confined to the city of Naples and its environs. The Sicilians in America vastly outnumber the Neapolitans. Thus in New York City for every one Camorrist you will find seven or eight Mafiusi. But they are all essentially of a piece, and the artificial distinction between them in Italy disappears entirely in America. Historically the Mafia burst from a soil fertilized by the blood of martyred patriots, and represented the revolt of the people against all forms of the tyrannous government of the Bourbons; but the fact remains that, whatever its origin, the Mafia to-day is a criminal organization, having, like the Camorra, for its ultimate object blackmail and extortion. Its lower ranks are recruited from the scum of Palermo, who, combining extraordinary physical courage with the lowest type of viciousness, generally live by the same means that supports the East Side "cadet" in New York City, and who end either in prison or on the dissecting-table, or gradually develop into real Mafiusi and perhaps gain some influence.