Florence is awash with images of the Annunciation, one of the most frequently depicted subjects in the history of art.
The Annunciation celebrates the moment the angel Gabriel announces to the Virgin Mary that she will conceive and become the mother of Jesus, the Son of God (Luke 1: 26-38).
In most images, Gabriel and Mary are accompanied by the Holy Spirit, which takes the form of a dove. However, very, very occasionally, the dove will be accompanied, or even replaced, by a tiny flying figure (often bearing a cross).
We can see such a figure, or homunculus, in a beautiful medieval painting of the Lignum Vitae (Tree of Life), which hangs in the Galleria dell' Accademia. It was painted, circa 1310-15, by Pacino di Bonaguida for the Convent of Monticelli.
The large wooden panel depicts a tree-shaped cross, which symbolises the Tree of Life. The scenes in the roundels hanging from its branches represent episodes from Christ's life. One of the roundels (lowest branch, left side) contains an image of the Annunciation, in which it is possible to discern a tiny figure, amidst rays of light, heading towards the Virgin Mary. The painter also depicts the same figure clinging to the Virgin's neck.
More than two centuries later, the Council of Trent (1545-63) would discourage such representations, as they could lead people to think that Christ was fully-formed before entering Mary's womb, thus making the Mother of God a mere passive receptacle, rather than an active participant, in the Incarnation.