it was commemorated only at Lauds, it is not commemorated at a Solemn Mass but only in private Masses. Exceptions again are Palm Sunday and the Vigil of Pentecost, at which no commemoration is made even at private Masses of an occurring Simple Feast, even if it was commemorated in the Office. A commemoration is made of a Sunday on which a Double Feast is celebrated. An Octave is commemorated on a Feast celebrated within it, unless the Feast in question is one of those excepted in the Rubric on Commemorations in the Breviary. So too when a Sunday is celebrated within an Octave." This was the first of eight subsections of the rubric of the Roman Missal regarding commemorations. A multiplicity of prayers had become so normal that even in Masses without any commemoration other prayers were added. The complicated rules in their regard were given in the seventeen subsections of the section De Orationibus of the Rubricae generales Missalis. This practice was abolished in 1955 under Pope Pius XII. Pope Pius X amended both De Commemorationibus and De Orationibus in 1910, as indicated in his Additiones et Variationes in Rubricis Missalis. The conclusion "Per Dominum nostrum ..." ("Through our Lord ...") or its variants were added only to the first and final prayers. Reduction of the mid-20th century By the decree Cum nostra hac aetate (De rubricis ad simpliciorem formam redigendis) of 23 March 1955 Pope Pius XII reduced the feasts previously of Simple rank to commemorations in the Office and Mass of the feast day or feria on which they occurred. He considerably simplified the practice of commemorations. The relevant rules were made uniform for both Mass and the Liturgy of the Hours. The basis for some of the previous distinctions was removed by decreeing that feasts, except those of the first and second classes, would no longer, in line with the tradition of Jewish origin that counts sunset as the start of a new day, begin with First Vespers. Commemoration was always to be made of Sundays, First-Class Feasts, Ferias of Advent and Lent, the September Ember Days, and the Major Litanies. Other commemorations were admitted on condition that the number of prayers should never exceed three. The verse of the short responsory in Prime and the doxology of hymns of a commemorated feast that had special ("proper") forms of these were no longer to be