The "Libera Nos" and Fraction of the Host

The Priest says silently:

LIBERA nos, quaesumus, Domine, ab omnibus malis, praeteritis, praesentibus, et futuris: et intercedente beata et gloriosa semper Virgine Dei Genitrice Maria, cum beatis Apostolis tuis Petro et Paulo, atque Andrea, et omnibus Sanctis, da propitius pacem in diebus nostris: ut ope misericordiae tuae adjuti, et a peccato simus semper liberi, et ab omni perturbatione securi. 

DELIVER us, we beg Thee, O Lord, from every evil, past, present, and to come; and by the intercession of the Blessed and glorious ever-Virgin Mary, Mother of God, and of the holy Apostles, Peter and Paul, and of Andrew, and of all the Saints, mercifully grant peace in our days, that through the assistance of Thy mercy, we may be always free from sin and safe from all disturbance.

Breaking the Host in half and then breaking off a small particle the Priest continues:

Per eundem Dominum nostrum Jesum Christum Filium tuum.  Qui tecum vivit et regnat in unitate Spiritus Sancti Deus,

Through the same Jesus Christ, Thy Son, our Lord, Who lives and reigns with Thee, in the unity of the Holy Ghost, God,

With raised voice, the Priest continues:

... per omnia saecula saeculorum.

R.  Amen.

... world without end.

R.  Amen.