Inhabited Initial P; Stammheim Missal, probably 1170s. Additional Info:A large initial P begins the introit, a chant sung by the choir as the priest enters the sanctuary, for the main Mass of Christmas day: Puer nat[us] est nobis (A boy is born for us). The musical notation written above the text indicates the chant melodies. The naked man and fox cavorting simply provide decoration among the fruit-bearing vines swirling through and around the letter.