After Jonas had got as many specimens as he could, from the wood pile, he used to cut others in the woods, when he happened to be there, of kinds which are not commonly cut for fuel. In this way he got, after a time, more than twenty different kinds, and when they were all neatly varnished and labelled, it made a very curious collection; and it was very useful, too, sometimes; for whenever the boys found any kind of a tree in the woods which they did not know, all they had to do, was to cut a branch of it off, and bring it to the museum, and compare it with Jonas's specimens. In this way, before long, they learned the names of nearly all the trees which grew in the woods about there. There was a curious circumstance which happened in respect to Rollo's hemlock-seed. It has already been said that this supposed hemlock-seed was really a chrysalis. Now, a chrysalis is that form which all caterpillars assume, before they change into butterflies; and the animal remains within, generally for some time, in a dormant state;--all the time, however, making a slow progress towards its development. Now, Rollo's great chrysalis remained in a conspicuous position, upon the middle shelf in the cabinet, for some weeks. Rollo always insisted, when he showed it to visitors, that it was a hemlock-seed. Jonas said he knew it was not; and he did not believe it was any kind of seed. But then he confessed that he did not know what it was, and Rollo considered that he had his father's authority for believing it to be a hemlock-seed, because his father had said he thought it might be so, judging however only by Rollo's description, without having seen it at all. Rollo always asserted very confidently that it was a hemlock-seed, and that he was going to plant it the next spring. In the mean time, the humble caterpillar within, unconscious of the conspicuous position to which he had been elevated, and the distinguished marks of attention he received from many visitors, went slowly on in his progress towards a new stage of being. When the time was fully come, he very coolly gnawed a hole in one end of his glossy shell, and laboriously pushed himself through, his broad and beautiful wings folded up compactly by his side. When he was fairly liberated, he stood for two hours perfectly silent and motionless upon the shelf, while his wings gradually expanded, and assumed their proper form and dimensions. It was rather dark, for the doors were closed; and yet sufficient light came through the crevices of Jonas's cabinet, to enable him to see the various objects around him, though he took very little notice of them. It was a strange thing for him to be shut up in such a place, with no green trees, or grass, or flowers around; but having never turned into a butterfly before, he did not know that there was any thing unusual in his situation.