Another natural effect of persecution was to check for a time the development of the ritual of the Church, and to render necessary the use of the simplest and most essential forms even in the celebration of the Holy Eucharist. The immense subterranean excavations at Rome, known by the name of the Catacombs, are an abiding {64} proof to us of the straits to which the primitive martyrs and their companions were reduced, when these sand-galleries were at once their Church and their burying-place, and in some instances the scene of their martyrdom also. [Sidenote: Church discipline very severe] The discipline of the Church was made extremely strict by the lengthened continuance of severe persecution. In those days when so many gave proof of the strength and reality of their Faith by their persevering endurance of unspeakable agonies, any shrinking back was looked upon as very unworthy cowardice, and as an almost hopeless fall, to be hindered if possible by the merciful severity of the Church as shown in warnings and punishments. Even those who had so far succumbed to trial as to give up the Sacred Books were called "Traditores," and considered as very criminal; those who had consented to pay Divine honours to the emperors or to the heathen gods, fell under still more severe censure, whilst such Christians as led sinful and immoral lives were considered most worthy of blame and punishment. Very heavy penances were laid upon all who thus fell away, in proportion to their guilt, before they were again admitted to the Communion of the Church; and in some extreme cases the punishment was life-long, and only allowed to be relaxed when the penitent was actually in danger of death. [Sidenote: for a time.] But this very severe discipline was temporary in its nature, as was the danger to the Church which called it forth, and was somewhat modified by the Letters of Peace which martyrs and confessors were allowed to give to excommunicated persons, authorizing their readmission to Church privileges. [Sidenote: Church government modified also for a time.] A temporary modification in the government of the {65} Church was also brought about by these times of suffering. Bishops, under the pressure of persecution, were sometimes forced to leave their flocks, or were first tortured and then banished, and their places had to be filled as far as they could be by the presbyters, with the advice of the distant Bishop; whilst at Rome, in the middle of the third century, there was a year's vacancy in the see after the martyrdom of Fabian, on account of the impossibility of bringing neighbouring Bishops into the midst of a storm which was raging with especial fury against the rulers of the Church. [1] St. John was a martyr in will, though not in deed, being miraculously preserved from injury in the caldron of boiling oil, into which he was plunged by order of Nero or Domitian.