We set out again in bright sunshine, and left behind us the deserted city of the plague. The next day the sun suddenly clouded, and looking up we saw that the cloud was rapidly moving over us and that it consisted of birds. We could distinguish the flash of the individual wings as they flickered in the sunbeams that broke through the ranks of the great army. We could hear far off the harsh or musical cries of the scouts and leaders, or the answering murmur of the embattled masses. At times we could see battalions form and reform in their flight, the van open its ranks and stretch out in long advancing line, and the rear ease their pace in order to cover the laggards. It was a marvellous sight, and the longer we listened the more distinctly could we hear the clang and whizz and creak of the myriads of wings. It was the annual migration northwards of the antarctic birds along the line of the submerged continent; so Noola explained. A large contingent for long ages had been inclined to settle each year on Limanora; but the storm-cone blew them onwards till they rejoined the main body. It was the storm-cone that was directing their flight now. He showed us how agitated were the rear battalions, how uncertain the beat of their wings, how irregular and shifting their formation. There we could see the strength of the blast bear stragglers out of their course, as they jerked their wings and uttered harsh cries; the spasmodic flash of the sunshine upon them was enough to show that they were bearing the brunt of some propelling storm. It took hours to clear the sky of this agitated cloud; but we set our course by its streaming flight, knowing that whence they were blown was our destination.