Jelaskan Mullion dari Katedral Santiago de Compostela dalam bahasa melayu

In the mullion is the seated figure of Saint James with a pilgrim's swagger stick, as patron of the basilica. St. James appears with a scroll which contains written Misit em Dominus (the Lord sent me). The column just above his head with a capital which represents the temptations of Christ.  On three of its sides, facing the inside of the temple, two kneeling angels pray. At the foot of the saint is another capital with the figures of the Holy Trinity. Under the Apostle represents the tree of Jesse, the name given to the family tree of Jesus Christ from Jesse, father of King David, is the first time that this subject is represented in religious iconography in the Iberian Peninsula. The column rests on a base where there is a figure with beard to his chest (perhaps an image of Noah) and two lions. At the foot of the central column at the top inside looking towards the main altar of the cathedral, is the kneeling figure of the himself Master Mateo, holding a sign that is written Architectus. This image is popularly known as «Santo dos croques» by the ancient tradition of students from hitting their heads against the figure for wisdom, a tradition that was adopted later by pilgrims, although steps are being taken to limit access to try to stop the deterioration that is why the work has suffered.