The different sections therein contained are partly of ecclesiastical and Christian origin, and partly secular and heathen. Of purely ecclesiastical origin, in addition to the table for calculating Easter, are the _Depositio Episcoporum_, the _Depositio Martyrum_, and the list of popes. The remaining sections fall into two classes: they are either entirely heathen, or they have interpolations of a Christian and ecclesiastical character. This is especially the case with the lists of consuls. Up to 753 U.C. they contain merely the names of the consuls, with notices of the dictators; from 753 U.C. to 55 A.D. four ecclesiastical notices have been interpolated, but none from thence onwards. These four notices relate to the date of Christ’s birth and death, the arrival of the Apostles Peter and Paul in Rome, and their death there. These notices, naturally, did not originally form part of the lists of consuls. Who added them? Philocalus himself or someone else? Since the list of consuls contains ecclesiastical interpolations, it is all the more remarkable that none have been added to the Calendar. Where else would we more naturally look for them, and where could they have been more easily introduced? Why did not Philocalus set down the birth of Christ here under the 25th December, the _Natalis Invicti_, since he considered it of sufficient importance to be interpolated into the lists of consuls, with which it is out of keeping? But if, it is objected, the date of Christ’s birth is also given in the _Depositio Martyrum_, let us examine this document more closely. As the title indicates, it contains only the days of the death and burial of Roman martyrs and other martyrs venerated in Rome in the earliest ages, _e.g._ Cyprian, Perpetua, Felicitas. To these there are added two exceptions: VIII. Kal. Jan. (the birth of Christ at Bethlehem) and VIII. Kal. Mart. (the feast of St Peter’s Chair). Neither of these belong in any sense to a _Depositio Martyrum_, and on this account, De Rossi wished to change the title of the document to _Feriale Ecclesiæ Romanæ_. But in this he was mistaken. The MSS. have the title _Depositio Martyrum_ alone, and to change it would be arbitrary. The two days mentioned above, the 25th December and the 22nd February, must rather be struck out as later additions which do not belong to the document. That such entries do not appear in the Calendar is explained, in my opinion, by the fact that soon afterwards succeeding emperors forbade the games of the circus and energetically suppressed heathen customs. When this had been done, the Calendar would no longer be of any practical use, and so it would not be worth while to make alterations in it. The other chronological pieces, however, had a permanent value, and it naturally occurred to those who used them later on to adapt them to the altered circumstances of the time.