The rubric of the _Ceremoniale Episcoporum_ (l. ii. c. xxiii., n. 27) makes no mention of the assistant priest, supposes that the bishop himself takes the ostensorium from the altar, and expressly declares that he himself replaces it on the corporal. "Accedat ad altare et accepto tabernaculo seu ostensorio cum sanctissimo Sacramento, illud ambabus manibus velatis elevatum tenens, vertens se ad populum, cum illo signum crucis super populum ter faciet nihil dicens. Quo facto iterum deponet sanctissimum Sacramentum super altare". We read in the _Instructio Clementina_ (§ xxxi.): "The celebrant, on his knees, will take the humeral veil, and ascending the altar without attendants, after due reverence, will take the ostensorium in his hands, which are covered with the extremity of the humeral veil, and with it will give the benediction to the people; and having replaced the Blessed Sacrament on the corporal, will descend, and remain on his knees in his place. The deacon, or a priest with stole, will immediately, after due reverence, enclose the Blessed Sacrament in the tabernacle". This _Instructio_ has been explained by Cavalieri, Tetamo, and Gardellini, who thus express themselves-- "Sacerdos", says Cavalieri (t. iv., c. ix.), "ascendit ... ad altare, et ibi, facta genuflexione unico genu accipit in manibus coöpertis per ejusdem veli extremitates ostensorium.... Quando sacerdos ascendit ut supra altare, una cum eo ascendunt itidem sacri ministri, sed hi genuflectunt postea in ore suppedanei, ubi inclinati elevant pluvialis fimbrias dum sacerdos benedicit populum. In defectu autem ministrorum sacrorum id praestant sacerdos adjutor et caeremoniarius, vel alii clerici hinc inde genuflexi.... Celebrans data benedictione ... super corporale Sacramentum collocat ... et deinde facta genuflexione unico genu, descendit cum subdiacono ad infimum altaris gradum, ubi iterum cum eodem genuflexus, per eumdem subdiaconum, vel caeremoniarium exuitur velo humerali. Diaconus interim accedit ad altare, et facta genuflexione unico genu, tabernaculum aperit et in eo reponit Sacramentum, cui genuflexione iterum facta, surgens ostiolum claudit et postea descendit ad locum suum, ad quem cum accesserit, surgunt omnes.... Quod si ultra sacros ministros adsistat sacerdos alter, hic imposita sibi stola Sacramentum ut supra recondet, et diaconus cum celebrante pariter descendet, et ab eo removebit velum humerale". Tetamo (Append., e. iii., n. 48 et 49) thus speaks: