Commentators have suggested that "The Zoo" was mounted hastily to capitalize on the success of "Trial". For instance, Hughes writes, "Sullivan was so bitten by the stage bug that at the request of another manager he dashed off "The Zoo", with a librettist whose identity it would be kinder not to reveal since he afterwards did good work under a "nom-de-plume"." But McElroy wonders "how Sullivan came to discover and set this libretto, by a relative beginner, so quickly?" He notes that a 13 March 1875 gossip column in the "Athenæum" said that Sullivan was working on new music for a piece at the St. James's, although for a different opera. From this, McElroy speculates that Stephenson was already working on the libretto of "The Zoo" for the St. James, while Sullivan was still busy preparing for the opening of "Trial":