"Then will you please tell us what is the matter with them?"
"Sleepy grass!"
"Sleepy grass?" chorused the lads.
"Of course they're asleep all right," added Ned. "But whoever heard of sleepy grass?"
"He means they're sleeping on the grass," Stacy informed them.
"Ah! I begin to understand," nodded the Professor. "I think I know what the trouble is now. The guide is no doubt right."
The boys gathered around him, all curiosity.
"Tell us about it, Professor. We are very much mystified?" said the Pony Riders.
"A long time ago I remember to have read, somewhere, of a certain grass in this region that possessed peculiar narcotic properties—"
"What's narcotic?" interrupted Stacy.