"Who" says the protestant Casaubon "is so little versed in the writings of the fathers, as to be ignorant of the formulary used principally of the sacraments, the initiated understand what is said: it occurs at least fifty times in Chrysostom, and almost as frequently in Augustine". S. Fulgentius inserts in his answer to the deacon Ferrandus the following words of S. Augustine to the neophytes "This which you see on the altar of God you saw last night: but what it was, what it meant, and of what a great thing it contains the sacrament, you have not yet heard. What therefore you see is bread and the chalice. What your faith demands is, that the bread is the body of Christ, and the chalice contains the blood of Christ". S. Cyril of Jerusalem in his catechetical discourses addressed to the newly baptised inculcates in the strongest terms the doctrine of the real presence, but charges them most strictly not to communicate to the catechumens his instructions. In consequence of this practice the early fathers often speak obscurely of the B. Sacrament, and call it bread and wine and _fermentum_ after the consecration, though they clearly teach the _faithful_ the doctrine of the real presence[6]. [Sidenote: Liturgy of the Roman church.] Pope Innocent I, writing to Decentius at the beginning of the fifth century, attributes the liturgy of the Roman church to St. Peter. It was first written in the fifth century; and Pope Vigilius sending it in 538 to Profuturus derives it from Apostolic tradition. The most ancient sacramentary or liturgical work extant of the Roman church is that of Gelasius who was Pope from 492 to 496[7]. He collected prayers composed by more ancient authors, and also composed some himself: and this Gelasian compilation was reformed by Gregory the Great and reduced to one volume[8], which may be considered as the prototype of our present liturgy. The canon or most solemn part of the mass has been preserved inviolate ever since, as appears from the Ordines Romani written shortly after the time of S. Gregory, and also from the explanations of it written by Florus and Amalarius. This canon as well as the order of prayer are the same as those of Gelasius, as Palmer observes (Orig. liturg. vol. 1, p. 119,) and are also nearly identical with those of the sacramentary of S. Leo. The Ambrosian and African liturgies also were evidently derived at a very remote period from that of Rome. From such considerations as these Mr. Palmer proves the very ancient or apostolical origin of the "main order", the substance of the Roman liturgy. Origines liturg. vol. I, sect. VI. The author of the canon is unknown; yet we know the authors of some additions to the canon. Thus S. Leo I added sanctum sacrificium immaculatam hostiam, S. Gregory I, diesque nostros in tua pace disponas. [Sidenote: Review of the ceremonies of the mass.] [Sidenote: Mass of the catechumens, ambones, sermons.]