The five subjects chosen by Giovanni for his bas-reliefs are the "Nativity," the "Adoration of the Magi," the "Massacre of the Innocents," the "Crucifixion," and the "Last Judgment." In the "Nativity" our Lady is no longer the Roman matron of Niccola's conception, but a graceful mother, young in years, and bending with the weakness of childbirth.

Her attitude, exquisite by the suggestion of tenderness and delicacy, is one that often reappears in the later work of the Pisan school--for example, in the rough _abozzamento_ in the Campo Santo at Pisa, above the north door of the Duomo at Lucca, and at Orvieto on the facade of the cathedral; but it has nowhere else been treated with the same sense of beauty.

The "Massacre of the Innocents," compared with this relief, is a tragedy beside an idyll.

Here the whole force of Giovanni's eminently dramatic genius comes into full play.

Not only has he treated the usual incidents of mothers struggling with soldiers and bewailing their dead darlings, but he has also introduced a motive, which might well have been used by subsequent artists in dealing with the same subjects.
Herod is throned in one corner of the composition; before him stand a group of men and women, some imploring the tyrant for mercy, some defying him in impotent despair, and some invoking the curse of God upon his head.
In the "Adoration of the Magi," again, Giovanni shows originality by the double action he has chosen to develop.