Proceeding from these baths to the extremity of the Via del Macao, we find in a vineyard, a mound of earth said to be part of the _agger_ of Servius Tullius, and the range of arches stretching towards the gate of San Lorenzo, is part of the Marcian aqueduct, now carrying the Acqua Felice; but I shall reserve aqueducts and gates to a future letter, and pass on to the church of Santa Bibiena, where there are some ancient columns, and a statue of the saint by Bernini. It has been much admired, but like so many other works of this artist, fails in the want of apparent ease and simplicity of nature. By a gate which is not always open, we may pass into the inclosure containing the ruin, usually called the temple of Minerva Medica, rising in the midst of artichokes and brocoli. The principal remain is a large, domed, decagonal hall, a form not common in the Roman antiquities, with nine large niches, each occupying almost the whole of their respective sides, the tenth being the situation of the doorway; and a window over each. The dome is partly destroyed, and the remaining portion perforated in many places, shewing the ancient construction to have been formed by ribs tending to a centre, while the intervals are filled up with rubble. There are some remains of other rooms adjoining. The whole is overgrown with the lentiscus and other shrubs and plants. It forms a picturesque object, but it seems impossible to determine its primitive destination. Near this is the Columbarium, or sepulchre of the Aruntian family. You may think there is little resemblance between a tomb and a dove-cot, but this name arises from the little recesses, compared to pigeon-holes, which contain the cinerary urns. It is, I believe, the most perfect of any remaining, and accessible about Rome, but it is seldom that any body is in the way, to exhibit it, and I have not yet been able to obtain admission. We leave this vineyard just by the Porta Maggiore, and passing under the beautifully built, brick arch of the Claudian aqueduct, continue our walk to the Temple of Venus and Cupid, which stands in the garden of a convent. A part of the great niche is nearly all of this which is left standing. Some of the brick facing remains, and a few other foundations of walls, little above ground. The shattered piers and arches of the ancient aqueducts exhibited in these gardens, are perhaps more interesting than the fragment of the temple. By this, is the church of the holy cross, which I have already described to you, as that of the Santa Croce in Gerusalemme, and the Anfiteatro Castrense, which I mean to describe with the city wall, of which it forms part. We then pass under the wall among rows of trees, on turf now covered with the _Anemone hortensis_, to the church of St. John Lateran, stopping by the way to look at the Triclinium and the Scala Santa. After passing these objects we arrive at the baptistery of Constantine; the obelisk,