The country we had passed through during this day's route was extremely low, consisting of extensive plains divided by lines of small trees: the banks of the river, and the deep bights formed by the irregularity of its course, were covered with acacia bushes and dwarf trees. The river, at the spot where we stopped, wound along the edge of an extensive low plain, being at least six miles long and three or four broad; these I called Field's Plains, after the judge of the supreme court of this territory; they are the same which we saw from the top of Mount Amyot. The soil of these plains is a light clayey loam, very wet in many places; they were fringed round with that beautiful tree, the acacia pendula, which here seems to perform the part of the willow in Europe; the cypresses were also more frequent, and the banks of the river much lower than even those we passed yesterday. I cannot help thinking that the whole of this extensive region has been at some time or other under water, and that the present river is the drain by which the waters have been conveyed to lower grounds. It is evident that even now the plains (on those parts clear of trees) are frequently under water, and that at very high floods the wooded lands are so too, for it is almost impossible to distinguish any difference in their elevation; but the wooded lands, from being actually higher, seem to have given time for the growth of the diminutive timber with which they are covered, whereas the lower plains are too frequently covered to give time for such growth. May 10.--The horses having strayed in the night, and it being nearly noon before they were found, I determined to make this a halting day. These plains are much more extensive than I supposed yesterday, and many new plants were found on them. The river rose upwards of a foot during the night, and still continues to rise; a circumstance which appears very singular to me, there having been no rains of any magnitude for the last five weeks, and none at all for the last ten days. We are also certain that no waters fall into it or join it easterly for nearly one hundred and fifty miles. This rise must therefore be occasioned by heavy rains in the mountains, whence the river derives its source; but it is not the less singular, that during its whole course, as far as it is hitherto known, it does not receive a single tributary stream. Observed the latitude 33. 16. 33. S.