Poe chose a raven as the central symbol in the story because he wanted a "non-reasoning" creature capable of speech. He decided on a raven, which he considered "equally capable of speech" as a parrot, because it matched the intended tone of the poem. Poe said the raven is meant to symbolize "Mournful and Never-ending Remembrance". He was also inspired by Grip, the raven in Barnaby Rudge: A Tale of the Riots of Eighty by Charles Dickens. One scene in particular bears a resemblance to "The Raven": at the end of the fifth chapter of Dickens's novel, Grip makes a noise and someone says, "What was that—him tapping at the door?" The response is, Tis someone knocking softly at the shutter." Dickens's raven could speak many words and had many comic turns, including the popping of a champagne cork, but Poe emphasized the bird's more dramatic qualities. Poe had written a review of Barnaby Rudge for Graham's Magazine saying, among other things, that the raven should have served a more symbolic, prophetic purpose. The similarity did not go unnoticed: James Russell Lowell in his A Fable for Critics wrote the verse, "Here comes Poe with his raven, like Barnaby Rudge/ Three-fifths of him genius and two-fifths sheer fudge." The Free Library of Philadelphia has on display a taxidermied raven that is reputed to be the very one that Dickens owned and that helped inspire Poe's poem.