I had seen the PSYTACUS NOVAE HOLLANDIAE and the SHELL PARROQUET following the line of the shore of St.Vincent Gulf like flights of starlings in England, and although intervals of more than a quarter of an hour elapsed between the passing of one flight and that of another, they all came from the north and followed in the same direction.
Now, although I am quite ready to admit that the casual appearance of a few strange birds should not influence the judgment, yet I think that a reasonable inference may be drawn from the regular and systematie migration of the feathered races.

Now, if we were to draw a line from Fort Bourke to the W.N.W., and from Mount Arden to the north, we should find that they would meet a little to the northward of the Tropic, and as I felt assured of two lines of migration thus tending to the same point, there could be little doubt but that the feathered races migrating upon them rested at that point, for a time, so I was led to conclude that the country to which they went would in a great measure resemble that which they had left--that birds which delighted in rich valleys, or kept on lofty hills, surely would not go into deserts and into a flat country; and therefore it was that I was led to hope, that as the fact of large migrations from various parts of the continent to one particular part, seemed to indicate the existence either of deserts or of water to a certain distance, so the point at which migration might be presumed to terminate would be found a richer country than any which intervened.

On the late expedition, I accidentally fell into the line of migration to the north-west, and birds that I was aware visited Van Diemen's Land passed us, after watering, to that point of the compass.

Cockatoos would frequently perch in our trees at night, and wing their way to the north-west after a few hours of rest; and to the same point wild fowl, bitterns, pigeons, parrots, and parroquets winged their way, pursued by numerous birds of the Accipitrine class.

From these indications I was led still more to conclude that I might hope for the realization of my anticipations if I could force my own way to the necessary distance.
During our stay at Moorundi, the weather had been beautifully fine, although it rained so much in the hills.