What is the symbolic meaning of "the colosseum" in the short story "Roman Fever"?

As in many of her stories, here Wharton uses space, interior and exterior, to communicate both theme and something important about her characters. The coliseum is an artifact of an earlier day, both in the larger historical and ideological sense—a time when men fought and ruled each other brutally—but also a time that the two women spent together in Rome, “when their friendship and rivalry both began.” Here, now, in visiting Rome again, they can talk to each other, unlike when, at home in America, their privileged lives across the street from each other prevented such communication. This space proves both confining in its domesticity and divisive by class that regulates behavior in such a way that real communication is not possible. It is only in Romethat Mrs. Slade feels able to reveal the truth to Mrs. Ansley. This truth is that she sent Mrs. Slade a letter that tricked her into meeting Mrs. Ansley’s fiancé at the time, hoping she would catch the “Roman fever” and die.  Just as the men competed for their lives in the coliseum years ago, so these two women competed against each other for men in the same location. Wharton weaves together themes of rivalry and friendship through this symbol.