The sculpture on the side arch to the south is supposed by the above-quoted authorities to represent the conversion of the Gentile or pagan world, as that to the north represents that of the Jews. The keystone of the southern arch is occupied by two busts--the upper, with a beard, represents “the man Christ Jesus,” and the lower, a beardless youth, also Christ, but this time “the God-Christ.” To the right of these busts are sculptured horizontally four angels bearing little human figures, round which they have wrapped their flowing mantles, towards Paradise (_i.e._ the central arch). To the left, also placed horizontally, are four hideous demons--the nearest one to the keystone of the lower archivolt is crouching down, and has the limbs of two little human beings hanging from his jaws; the second, with the feet of an ox, is also maltreating human beings; the third, who has claws instead of feet, has four little figures suspended from his neck; the fourth, with human feet, is munching human beings, two at a time. These demons, in the opinion of Lopez Ferreiro, represent _not devils_ but violence, cruelty, rapine, and gluttony. Serpents are seen entwining some of the little figures; they are the passions which tyrannise over the unconverted. As I have said, Lopez Ferreiro was the first writer to interpret the symbolism of the _Pórtico de Gloria_ in this way. The fact that four angels blowing trumpets are sculptured at the four corners of the narthex led some critics to believe that the whole was nothing more nor less than the hackneyed theme of the Last Judgment; they took the beardless bust of Christ to represent St. Michael, though they were obliged to admit that his scales were not visible. Some have thought that the monsters represented purgatory, but this is not likely, as purgatory was not represented either in painting or sculpture until the fifteenth century, except metaphorically (which it was from the earliest times).[153] Roulin strongly opposes the interpretation of Lopez Ferreiro, and remarks that the theme of the _Pórtico de Gloria_ is well known to iconography, and that it is the same as that found in many other cathedrals. He is convinced that the angels carrying the instruments of the Passion, or of Christ showing His wounds, are never represented, except when the subject is the Last Judgment. With regard to the Jews behind the tore he remarks: “Il faut convenir que pareille representation est insolite,” but adds that there are various ways in which it might be interpreted, one being Death and the Resurrection; the tore would then be the emblem of death, and the green foliage that of the green pastures of Paradise. As for the beardless bust on the other arch representing Christ--a bust with neither beard nor nimbus is, in his opinion, a thing unheard of after the middle of the eleventh century! The extension of the theme of the Last Judgment to three arches is, he owns, the point which distinguishes the _Pórtico de Gloria_ of