These three plaques represent the following:
The doves were inspired by Pliny's Doves, reproducing an ancient Roman mosaic panel in the Capitoline Museum, Rome. Described by Pliney, "Natural History XXXVII", "a marvellous dove drinking and casting the shadow of its head on the water. Other doves are pluming their feathers in the sun on the lip of the goblet". Found in the ruins of Hadrian's villa at Tivoli in 1737, the mosiac, as one of the most remarkable attractions in Rome, was copied many times by the makers of shell cameos and as here of glass micrmosaics for jewellery and box lids.
The swan represents a departure from the neo-classical themes of the eighteenth century which were essentially static in character, but taken from nature, these bird and animal studies introduce a more lively note to mosaic compositions.
Alvar Gonzales Palacios suggests that the original of the popular fox motif was designed by the Roman artist Belloni. Another version, in the Hermitage Museum, is attributed to the great mosaicist, Giacomo Raffaelli (1743-1846).
Cf. Alvar Gonzales Palacios, "The Art of Mosaics, Selections from the Gilbert Collection, 1977, nos. 28 and 39
D. Petochi, "I Mosaici Minuti Romani", 1981, page 95