It may be noted here, that, in the recitation of this Office, which is, for most priests, the only choral recitation of liturgy, care should be taken to select the proper nocturn or nocturns. "In the general rubrics of the Breviary (Tit. XIX. n. 2) it is stated that the invitatory is not to be said in _Officio Defunctorum_ per annum, excepto die Commemorationis omnium fidelium defunctorum, ac in die obitus seu depositionis defuncti et quandocunque dicuntur tres nocturni. When, therefore, only one nocturn is recited, the invitatory is to be omitted except on the dies obitus seu depositionis." In this latter case, even though the body is not present--for some special reason, such as contagious disease--the invitatory is not to be omitted. "On any other occasion, no matter how solemn or privileged, such as the seventh, thirtieth, or anniversary day, when only one nocturn is recited, the invitatory must not be included. This is clear, not only from the rubrics of the Breviary and Ritual (Tit. VI., cap. IV.) but also from certain answers of the Congregation of Rites" (_Irish Eccles. Record_, December, 1913). Dom Baudot's _The Roman Breviary_ gives in an appendix, pp. 239-252, "tables showing the date at which each saint was inserted in the Roman Breviary, the rank given to his festival, and the variations it has undergone. It is often difficult to give precise dates." ROGATION DAYS, EMBER DAYS AND LITANIES. "Litanies were solemn supplications instituted to implore the blessing of Heaven on the fruits of the earth. It was customary to recite them in the spring, that is, the season of late frosts, so much dreaded by the cultivators of the soil.... The people marched in procession to the spot, chanting the while that dialogue prayer which we call a litany, elaborated, according to circumstances, into a long series of invocations, addressed to God and to angels and saints." "The day set apart for this purpose at Rome was the 25th April, a traditional date, being that on which the ancient Romans celebrated the festival of the Robigalia.... "The most ancient authority for this ceremony is a formulary for convoking it, found in the Register of St. Gregory the Great, which must have been used in the first instance in the year 598" (Duchesne, _Christian Worship_, chap, viii., n. 9).