Robinson did not know the names of many of the birds he saw on the island. He had to make names for them. The strangest thing he saw on his journey was the nest of what he called the yellow-tail. This bird lives in colonies and makes its nest at the ends of the long leaves of the mountain palm. When he first saw these queer looking sacks hanging from the leaves he was amazed. He had never seen so strange a sight. From the end of each great leaf hung a long, closely woven nest. Robinson could not make out at first what they were. Soon, however, he saw the birds come out of the mouths of the nests. Here, one hundred feet from the ground, they hung their nests. But they were perfectly safe. He had not gone far from the tree in which the yellow tails had their nests when he was suddenly startled by a voice crying, "Who, who are you?" Robinson was greatly frightened and hid beneath the drooping branches of a cedar tree. He feared every moment that the owner of the voice would make his appearance. But it kept at a distance. Every few minutes from the depths of the forest would come the doleful cry, "Who, who are you?" Robinson did not dare to stir from his hiding place. He remained there over night. After the night came on he heard the strange voice no more. The next day he renewed his journey. He saw many birds that were wholly strange to him. There was a kind of wild pigeon that built its home in a hole in the rock. It was a most beautiful bird with long, slender, graceful feathers in its tail. He saw the frigate bird soaring high above the island. The number and beauty of the humming-birds amazed Robinson. They were of all colors. One had a bill in the shape of a sickle. The most brilliant of them all was the ruby-crested humming-bird. Near noon, while Robinson was shielding himself from the scorching heat of the sun in a deep, shaded glen, he was startled again by the strange voice crying, "Who, who, who are you?" He lay quite still, determined if possible to allow the voice to come, if it would, within sight. He heard it slowly coming up the glen. Each time it repeated the cry it sounded nearer. At last he saw spying at him through the boughs of the tree under which he was lying a large bird with soft, silky feathers of green and chestnut. "Who, who, who are you?" said the bird. Robinson could not help but laugh. He had been frightened at the cry of a bird.