"Take exercise! take exercise!" said Mr. Austin with emphasis.
"I think I will," said Ned.
Physical exercise, after all, fitted in with his ideas, and that afternoon he worked hard at all the gymnastic feats possible within the three rooms to which they were confined. De Zavala came in and expressed his astonishment at the athletic feats, which Ned continued with unabated zeal despite his presence.
"Why do you do these things?" he asked in wonder.
"To keep myself strong and healthy. I ought to have begun them sooner. The Mexican air is depressing, and I find that I am losing my appetite."
De Zavala's eyes opened wide while Ned deftly turned a handspring. Then the young American sat down panting, his face flushed with as healthy a color as one could find anywhere.
"You'll have an appetite to-night," said Mr. Austin. But to his great amazement Ned again played with his food, eating only half the usual amount.
"You're surely ill," said Mr. Austin. "I've no doubt de Zavala would allow us to have a physician, and I shall ask him for one."
"Don't do it, Uncle Steve," begged Ned. "There's nothing at all the matter with me, and anyhow I wouldn't want a Mexican doctor fussing over me. I've probably been eating too much."
Mr. Austin was forced to accede. The boy certainly did not look ill, and his appetite was bound to become normal again in a few days. But it did not. As far as Mr. Austin could measure it, Ned was eating less and less. It was obvious that he was thinner. He was also growing much paler, except for a red flush on the cheek bones. Mr. Austin became alarmed, but Ned obstinately refused any help, always asserting with emphasis that he had no ailment of any kind. But the man could see that he had become much lighter, and he wondered at the boy's physical failure. De Zavala, also, expressed his sorrow in sonorous Spanish, but Ned, while thanking them, steadily disclaimed any need of sympathy.