In this 1905 humorous short story, confusion over what a guinea pig truly is causes trouble for a stubborn railway agent.

Mr. Morehouse would very much like to collect his two guinea pigs from the express office of the Interurban Express Company. However, railway agent Mike Flannery wants to charge him the  livestock rate of thirty cents—not the lower pet rate of twenty-five cents. “Pigs is pigs,” he tells an enraged Mr. Morehouse, believing that “guinea” is merely an indication of the pigs’ national origin. With both men refusing to budge, the guinea pigs remain in Flannery’s office where he is forced to feed and care for them. Just when Flannery thinks he’s in the clear, his problems begin to multiply . . .