The symbolism of the shepherd's staff is naturally the leading thought in the minds of the mystics. It was probably, however, considered too obvious, and they cast about to find yet further secret meanings. Thus, Honorius notices that the Lord commanded the apostles to 'take nothing save a staff only' when they were going out to preach, and then says that 'the staff which sustains the feeble signifies the authority of teaching,' and much more to the same effect. Innocent III says that the point is sharp, the middle straight, the top curved, to indicate that the priest should spur on the idle, rule the weak, collect the wandering. He further explains the fact that the Pope does not bear the pastoral staff by telling us that 'the blessed St Peter sent his staff to Eucharius, the first bishop of Trèves, whom he had sent, together with Valerius and Maternus, to preach the Gospel among the Germans. Maternus succeeded him in the bishopric; he had been raised from the dead by the staff of St Peter. And this staff is preserved with great reverence in the church of Trèves.' St Thomas Aquinas supplements this piece of information by telling us that for this reason the Pope carries the pastoral staff when pontificating in Trèves.[75] The episcopal staff is alleged to have borne the following inscriptions: round the crook, 'Cum iratus fueris misericordiae recordaberis'; on the ball below the crook, 'Homo'; on the spike at the bottom, 'Parce.' By these inscriptions the bishop was warned that he was but a man himself; that in wrath he should remember mercy; and that he should spare, even when administering discipline. Whether these warnings were invariably effective is a matter into which we will not inquire. XVII. _The Tunicle._—This was simply a small variety of the dalmatic, appropriated to the use of subdeacons and bishops. It differed from the dalmatic merely in being somewhat smaller. It was made of silk or of wool, and first appears about the year 820 as a subdeacon's vestment; but it is considerably later than this that it appears as a bishop's garment. In the ninth century bishops appear with but one vestment—the alba—under the chasuble; between the ninth and eleventh centuries the dalmatic makes its appearance; and it is not till about 1200 that we find the tunicle illustrated in paintings or effigies of bishops. A reference to the table given in the early part of the present chapter will show that the literary evidence points in the same direction. The tunicle did not escape the common fate of all the vestments of the mediaeval church, and it, too, became overlaid with needlework, first in a strip across the breast of the subdeacon, then (as this would not show under the vestments of the bishop) on the rest of the surface. The tunicle on Bishop Goodrick's brass at Ely Cathedral—one of the latest representations of this vestment in England—is as richly embroidered as the dalmatic.