It wearily dragged itself down to the edge of the pool, and looked backwards to the Kangaroo and Dot, who called out "Good-bye" to it. Its eyes were dim with tears, for it was still thinking of the Iguanodon and ichthyosaurus, and of the good old days before the Flood.
"It breaks my heart to think that they are all fossils," it exclaimed, mournfully shaking its head. "Fossils!" it repeated, as it plunged into the pool and swam away. "Fossils!" it cried once more, in far, faint accents; and a second later it dived out of sight.
For several moments after the Platypus had disappeared from view, the Kangaroo and Dot remained just as it had left them. Then Dot broke the silence.
"Dear Kangaroo," said she, "what was that song about?"
"I don't know," said the animal wistfully, "no one ever knows what the Platypus sings about."
"It was very sad," said Dot.
"Dreadfully sad!" sighed the Kangaroo; "but the Platypus is a most learned and interesting creature," she added hastily. "Its conversation and songs are most edifying; everyone in the bush admits it."
"Does anyone understand its conversation?" asked Dot. She was afraid she must be very stupid, for she hadn't understood anything except that Willy Wagtail could help them to find her way.
"That is the beauty of it all," said the Kangaroo, "the Platypus is so learned and so instructive, that no one tries to understand it; it is not expected that anyone should."