15. Onesicritus, for example, says of Taprobane, that its magnitude is 5000 stadia, without distinction of length or breadth, and that it is distant twenty days’ sail from the continent, but that it was a voyage performed with difficulty and danger by vessels with sails ill constructed, and built with prows at each end, but without holds and keels;[337] that there are other islands between this and India, but that Taprobane lies farthest to the south; that there are found in the sea, about the island, animals of the cetaceous kind, in form like oxen, horses, and other land-animals. 16. Nearchus, speaking of the accretion of earth formed [CAS. 691] by the rivers, adduces these instances. The plains of Hermes, Caÿster, Mæander, and Caïcus have these names, because they have been formed by the soil which has been carried over the plains by the rivers; or rather they were produced by the fine and soft soil brought down from the mountains; whence the plains are, as it were, the offspring of the rivers, and it is rightly said, that the plains belong to the rivers. What is said by Herodotus[338] of the Nile, and of the land about it, may be applied to this country, namely, that it is the gift of the Nile. Hence Nearchus thinks that the Nile had properly the synonym of Egypt. 17. Aristobulus, however, says, that rain and snow fall only on the mountains and the country immediately below them, and that the plains experience neither one nor the other, but are overflowed only by the rise of the waters of the rivers; that the mountains are covered with snow in the winter; that the rains set in at the commencement of spring, and continue to increase; that at the time of the blowing of the Etesian winds they pour down impetuously, without intermission, night and day till the rising of Arcturus,[339] and that the rivers, filled by the melting of the snow and by the rains, irrigate the flat grounds.