So they went across to the other side of the little island and started opening oysters. But not another pearl did they find.
"Where are the oyster beds around here?" asked the Doctor.
"Between this island and the next," said the spoonbill. "I don't fish for them myself because I'm not a deep diver. But I've seen other kinds of sea birds fishing in that place—just about half way between this island and that little one over there."
"I'll go out with her, Doctor," said Dab-Dab, "and do a little fishing on my own account. I can dive pretty deep, though I'm not a regular diving duck. Maybe I can get some pearls for you."
So Dab-Dab went out with the spoonbill and started pearl fishing.
Then for a good hour and a half the faithful housekeeper fished up oyster after oyster and brought them to the Doctor on the island. He and the animals found opening them quite exciting work, because you never knew what you might discover. But nothing was found in the shells but fat oysters and thin oysters.
"I think I'd like to try a hand at diving myself," said the Doctor, "if the water is not too deep. I used to be quite good at fishing up sixpences from the bottom of the swimming pool when I was a boy."
And he took off his clothes, got into the canoe and paddled out with the animals till he was over the oyster beds. Then he dove right down into the clear green water, while Jip and Gub-Gub watched him with intense interest.
But when he came up, blowing like a seal, he hadn't even got an oyster. All he had was a mouthful of seaweed.
"Let's see what I can do," said Jip. And out of the canoe jumped another pearl fisherman.