The interior of the sacristy is planned with a noble sense of unity.  For the purpose of illuminating a gallery of statues, the lighting may be praised without reserve; and there is no doubt whatever that Michelangelo intended every tabernacle to be filled with figures, and all the whitewashed spaces of the walls to be encrusted with bas-reliefs in stucco or painted in fresco.  The recesses or niches, taking the form of windows, are graduated in three degrees of depth to suit three scales of sculptural importance.  The sepulchres of the Dukes had to emerge into prominence; the statues subordinate to these main masses occupied shallower recesses; the shallowest of all, reserved for minor statuary, are adorned above with garlands, which suggest the flatness of the figures to be introduced.  Architecturally speaking, the building is complete; but it sadly wants the plastic decoration for which it was designed, together with many finishing touches of importance.  It is clear, for instance, that the square pedestals above the double pilasters flanking each of the two Dukes were meant to carry statuettes or candelabra, which would have connected the marble panelling with the cornices and stucchi and frescoed semicircles of the upper region.  Our eyes are everywhere defrauded of the effect calculated by Michelangelo when he planned this chapel.  Yet the total impression remains harmonious.  Proportion has been observed in all the parts, especially in the relation of the larger to the smaller orders, and in the balance of the doors and windows.  Merely decorative carvings are used with parsimony, and designed in a pure style, although they exhibit originality of invention.  The alternation of white marble surfaces and mouldings with pietra serena pilasters, cornices, and arches, defines the structural design, and gives a grave but agreeable sense of variety.  Finally, the recess behind the altar adds lightness and space to what would otherwise have been a box.  What I have already observed when speaking of the vestibule to the library must be repeated here:  the whole scheme is that of an exterior turned outside in, and its justification lies in the fact that it demanded statuary and colour for its completion.  Still the bold projecting cornices, the deeper and shallower niches resembling windows, have the merit of securing broken lights and shadows under the strong vertical illumination, all of which are eminently picturesque.  No doubt remains now that tradition is accurate in identifying the helmeted Duke with Lorenzo de’ Medici, and the more graceful seated hero opposite with Giuliano.  The recumbent figures on the void sepulchres beneath them are with equal truth designated as Night and Day, Morning and Evening.  But Michelangelo condescended to no realistic portraiture in the statues of the Dukes, and he also meant undoubtedly to treat the phases of time which rule man’s daily life upon the planet as symbols for far-reaching thoughts connected with our destiny.  These monumental