For as he recalled his own adventure, it was evident to him that he had had a very narrow escape from suffocation, the mist being evidently a volcanic exhalation, rising from the earth in a long low portion extending for miles in a curve, perhaps being the extent to which the mountain had reached in some far-off time; in fact, there might have been an old crater here only a little raised above the sea.

But he shook off the despondency, and fought back the idea that his companions might have been overcome by the escaping gases, and forced himself to believe that if they were not somewhere on his side hidden from him by the trees, they had safely made their way back to the side from which they had started.

He knew he had no grounds for all this, as they must necessarily have been as much confused and overcome as he, but he came to the conclusion which he wished to be true, and after mounting to the highest bit of ground in his immediate neighbourhood, he hailed again and again, listening patiently in the intervals for some reply.

There was a musical piping whistle twice, and once he was aware of a curious grunting sound from some trees away to his right, and this was repeated on his hailing again. Then all was silent once more, and he stood, now looking round, now watching the line of mist from which he hoped to see his companions emerge.

There were moments when he felt convinced that they had reached the same side as he, and he set to work hurrying here and there as fast as the tangled growth of the pathless forest would allow, hailing from time to time, but all in vain, and at last, dripping with perspiration, panting and exhausted, he leaned against a tree.

He had something else to combat now besides weariness, a terrible feeling of depression, for the thought would keep on coming with constant recurrence that his friends had perished in the mist.

He mastered this thought as the feeling of exhaustion passed away, and was ready to laugh at the sense of dread caused by his loneliness. For, as he told himself, it was probably all imagination respecting his friends, and there was nothing to mind. He was only separated from the vessel by a comparatively short distance, and sooner or later an effort would be made to reach him. It might not be possible to pass through the foul gases, but surely the long line of mist could be circumvented; and he climbed to the highest point he could then find to try and see its ends.

There was nothing to fear, for he had his gun, plenty of ammunition, and a little provision left. The place was wonderfully beautiful, and offered a tempting number of objects to a naturalist, as soon as he could make himself sufficiently calm to begin to investigate.

And it was in the above spirit, feeling quite certain that sooner or later he would see a party coming in search of him, he began to examine, turning his attention first towards the huge volcano, which rose up grim and forbidding away to the north, with the globular cloud poised over its highest part, which seemed as if cut right across in a slope.

Once he could turn his thoughts from the idea of peril, he began to be interested and eager; for he was in the position so dear to a lover of nature, there in a land surrounded by bird and insect forms for the most part entirely fresh to him.