In the whole of the interior there were no cities, but only dwellers in tents, and the most part of the Arabian tribes led a nomadic life, for Arabia was very rich in animals of various kinds, so that the Arabs could easily live on them without cultivating corn. They had large herds of cattle, and with these they wandered over immeasurable plains. In conclusion, Diodorus praises the fertility and beauty of a well-watered palm-grove in the peninsula between the northern bays of the Arabian Sea, which the barbarians had very justly consecrated to the gods, as it lay in the midst of a very hot and desert land, surrounded by a wilderness. There was an old altar there of hard stone inscribed with very ancient letters, which no one could read. A man and woman presided for life as priests over this holy palm-grove, and every four years the neighbouring Arab tribes sacrificed hecatombs of goodly camels there.[432] Pliny observes: "Strange to say, the Arabs live about equally on plunder and on trade; what they get from their forests (by which is meant the products of the date-palms and the fruit-trees of South Arabia) and from the sea they sell; but they purchase nothing in return."[433] "The Arabs," says Ammianus Marcellinus, "extend from the Euphrates to Egypt. They are half-naked, with only a coloured apron round the body reaching to the middle. Every man is a warrior. On their swift fine-limbed horses and their camels they ride in every direction. They do not continue long in any one place: without settled abodes they wander to and fro, and their whole life is nothing but a flight. Of bread and wine the most part of them know nothing whatever."[434]