Like the water and the islands, the sky was now cleared of birds, and not a swallow remained. Felix asked himself if he were running into some unknown danger, but he could not conceive any. The only thing that occurred to him was the possibility of the wind rising to a hurricane; that gave him no alarm, because the numerous islands would afford shelter. So complete was the shelter in some places, that as he passed along his sail drew above, while the surface of the water, almost surrounded with bushes and willows, was smooth. No matter to how many quarters of the compass the wind might veer, he should still be able to get under the lee of one or other of the banks. The sky remained without clouds; there was nothing but a slight haze, which he sometimes fancied looked thicker in front or to the eastward. There was nothing whatever to cause the least uneasiness; on the contrary, his curiosity was aroused, and he was desirous of discovering what it was that had startled the birds. After a while the water became rather more open, with sandbanks instead of islands, so that he could see around him for a considerable distance. By a large bank, behind which the ripple was stilled, he saw a low wave advancing towards him, and moving against the wind. It was followed by two others at short intervals, and though he could not see them, he had no doubt shoals of fishes were passing and had raised the undulations. The sedges on the sandbanks appeared brown and withered, as if it had been autumn instead of early summer. The flags were brown at the tip, and the aquatic grasses had dwindled. They looked as if they could not grow, and had reached but half their natural height. From the low willows the leaves were dropping, faded and yellow, and the thorn bushes were shrivelled and covered with the white cocoons of caterpillars. The farther he sailed the more desolate the banks seemed, and trees ceased altogether. Even the willows were fewer and stunted, and the highest thorn bush was not above his chest. His vessel was now more exposed to the wind, so that he drove past the banks and scattered islands rapidly, and he noticed that there was not so much as a crow on them. Upturned mussel-shells, glittering in the sunshine, showed where crows had been at work, but there was not one now visible.