Black vestments are to be worn on days of penitence and abstinence, and also on the Commemorations of the dead. They were also worn during Advent and Lent, except, of course, on festivals falling within those seasons. With regard to the Holy Innocents some decided in favour of black, some in favour of red, but the Roman pontiff decided for violet. For ferias and ordinary days the colour was green. One might, in addition, wear scarlet for red, violet for black, and yellow for green. In Durandus († 1296) we find the same rule, in parts verbally identical with the above. The only point to notice in regard to what he says is that he says black vestments are to be worn on Rogation days, violet seems to have the preference over black for Advent and Lent, and the use of the former colour is represented as peculiar to the Roman Church.[838] There is accordingly nothing strange in the circumstance that in the more ancient rituals, only _vestes solleminores_ in general are prescribed for Maunday Thursday, without reference to colour. The Roman use,[839] from the beginning, was to use white on this day, and this superseded the customs observed elsewhere.[840] V (p. 79) THE WORD MASS AS A NAME FOR THE SACRIFICE OF THE ALTAR The term mass does not owe its position to theology, but became established in the course of centuries by popular usage. The most ancient writers of the church speak frequently, and with all the precision desirable of the holy sacrifice of the altar, but they speak of it by other names which fully indicate its essential character, such as _oblatio_ and _sacrificium_, or even _sacramenta_ and _collecta_. These two last names have a more general significance; _collecta_ is the late Latin abbreviation for _collectio_, and means an assembly of men for some given purpose, in this case for divine service. _Colligere_ appears in the same sense in the Latin translation of Irenæus and in Tertullian; the substantive is found in Jerome and other ancient authors; a survival of this primitive usage appears in the name _collecta_ given to the first prayer of the Mass.[841] It owes its name of _collecta_ to the fact that according to the most ancient ritual it formed the commencement of the Mass. In the service-books, _collecta_ was merely a name which served to distinguish the prayers of the Mass from those which preceded or followed. According to the Roman rite, the Mass began with the prayer of the priest at the altar as soon as the _invitatorium_ sung by the choir was finished, the psalm _Judica me_, the _Confiteor_, the _Kyrie_ and _Gloria_ being later additions. Thus the name _collecta_ became attached to this opening prayer, and is so given to it in most mediæval and Roman missals, until the reform under Pius V., when it was replaced by the name _oratio_ now in use. At the same time the name _postcommunio_ replaced the older title _ad complendum_. Whenever we find in prayer-books and