Daisy had charge of it and would not let him take it out of her hands. She unfolded napkins, and permitted the Captain to help himself when she had all things ready. Then bread and butter and salad were found to be very refreshing. But while Daisy eat, she looked at the trilobite. "Please tell me what it is, Capt, Drummond." "It is a Crustacean." "But you know I don't know what a Crustacean is." "A Crustacean, is a fellow who wears his bones on the outside." "Capt. Drummond! What do you mean?" "Well I mean that, Daisy. Did you never hear of the way soldiers used to arm themselves for the fight in old times? in plates of jointed armour?" "Yes, I know they did." "Well these fellows are armed just so--only they do not put on steel or brass, but hard plates of bone or horn that do exactly as well, and are jointed just as nicely." "And those are Crustaceans?" "Those are Crustaceans." "And was this thing armed so?" "Splendidly. Don't you see those marks?--those shew the rings of his armour. Those rings fitted so nicely, and played so easily upon one another, that he could curl himself all up into a ball if he liked, and bring his armour all round him; for it was only on his back, so to speak." "And how came he into this rock, Capt. Drummond?" "Ah! how did he?" said the Captain, looking contentedly at the trilobite. "That's more than I can tell you, Daisy. Only he lived before the rock was made, and when it was made, it wrapped him up in it, somehow; and now we have got him!" "But, Capt. Drummond I----" "What is it?" "When do you suppose this rock was made?" "Can't just say, Daisy. Some rocks are young, and some are old, you know. This is one of the old rocks." "But how do you know, Capt. Drummond?" "I know by the signs," said the Captain. "What is an old rock? how old?" "I am sure I can't say, Daisy. Only that a _young_ rock is apt to be a good deal older than Adam and Eve." "How can you tell that?" "When you see a man's hair grey, can't you tell that he is old?" "But there are no grey hairs in rocks?" said Daisy. "Yes, there are. Trilobites do just as well." "But I say," said Daisy laughing, "how can you tell that the rock is old? You wouldn't know that grey hairs were a sign, if you saw them on young people." "Pretty well, Daisy!" said the Captain, delighted to see her interested in something again;--"pretty well! But you will have to study something better than me, to find out about all that. Only it is true." "And you were not laughing?" "Not a bit of it. That little fellow, I suppose, lived a thousand million years ago; may as well say a thousand as anything." "I can't see how you can tell," said Daisy, looking puzzled. "That was a strange old time, when he was swimming about--or when most of them were. There were no trees, to speak of; and no grass or anything but sea-weed and mosses; and no living things but fishes and oysters and such creatures?" "Where were the beasts then, and the birds?"