Osseo made no answer; but when he came to the log he paused again. It was the trunk of a huge oak-tree blown down by the wind. There it had lain for years, just as it fell; and the leaves of many summers lay thick upon it. There was one thing, though, the sisters had not noticed.. The tree-trunk was not a solid one, but hollow, and so big around that a man could walk inside it from one end to the other without stooping.