It is worn by bishops, priests, deacons and subdeacons under the other eucharistic vestments, either at Mass or at functions connected with it.
It is worn girdled by bishops and priests in all rites, by subdeacons in the Greek and Coptic rites.
Taking the other orders downwards: deacons wear amice, alb, girdle, stole, maniple' and dalmatic; subdeacons, amice, alb, girdle, maniple and tunicle; the vestment proper to the minor orders, formerly the alb, is now the surplice or cotta.
These are 46 presbyters, 7 deacons, 7 subdeacons, 42 acolytes, 52 exorcists and readers, together with doorkeepers.
The subdeacons, no doubt, became a necessity when the deacons, whose number was limited to seven in memory of their original institution, were no longer equal to their duties in the " regions " of the imperial city, and left their lower work, such as preparation of the sacred vessels, to their subordinates.
Those of subdeacons and readers, and this holds good of the Oriental churches generally, with the single exception of the Armenians.'
The Latins, and Armenians who have borrowed from the Latins, have subdeacons, acolytes, exorcists, readers and doorkeepers.
In the Maronite, Syrian, and Nestorian Churches subdeacons also wear the stole, and among the Maronites the lectors as well.
By the 13th century, with the final development of the ritual of the Mass, the chasuble became definitely fixed as the vestment of the celebrating priest; though to this day in the Roman Church relics of the earlier general use of the chasuble survive in the planeta plicata worn by deacons and subdeacons in Lent and Advent, and other penitential seasons.
In the West the high altar was moved to the east end (the presbyterium) with a space before it for the assisting deacons and subdeacons (the chancel proper) railed off as a spot peculiarly holy (now usually called the sanctuary); between this and the nave, where the laity were, was the choir, with seats for the clergy on either side.
In the Eastern churches the only vestment that has any true analogy with the dalmatic or liturgical upper tunic is the sakkos, the tunic worn by deacons and subdeacons over their everyday clothes being the equivalent of the Western alb.
This ceased at Rome at the same time as the apparel disappeared; but two relics of it survive - (I) in the directions of the Missal for putting on the amice, (2) in the ordination of subdeacons, when the bishop lays the vestment on the ordinand's head with the words, "Take the amice, which symbolizes discipline over the tongue, &c."
This, so far as its potestates ordinis are concerned, is divided into seven orders: the three " major orders " of bishops and priests, deacons, and subdeacons (bishops and priests forming two degrees of the ordo sacerdotium), and the four " minor orders " of acolytes, exorcists, readers, and door-keepers.
They speak of the ordination of bishops (the so-called Clementine Liturgy is that which is directed to be used at the consecration of a bishop, cc. 5-15), of presbyters, deacons, deaconesses, subdeacons and lectors, and then pass on to confessors, virgins, widows and exorcists; after which follows a series of canons on various subjects, and liturgical formulae.
Here we find "bishops and priests allowed to retain the wives whom they may have had before ordination, but not to marry in orders; the lower grades, deacons, subdeacons, &c., allowed to marry after entering the church; but all were to be husbands of but one wife, who must be neither a widow, a divorced woman nor a concubine" (Lea i.
Meanwhile, as has been said above, the custom of open marriage among clergy in holy orders (priests, deacons and subdeacons) was gradually stamped out.