 In Naharro's volume of plays, "Propaladia" (published in 1517 in Naples), he uses what is called an "introito" as a prologue spoken by a comic shepherd.Furthermore, traces of the beginnings of the introitos are seen in medieval mystery plays of the 15th Century in Spain in the eclogues, short poems, ("églogas)" of Juan del Encina using a similar comic shepherd character within a Christmas play.Introitos and "argumentos", another similar form of prologue used by Naharro, are both early forms of the loa that provide a summary or explanation of the comedia that follows it.