ourselves."

"I won't say yes to that yet, sir," said Griggs dryly; "not till we've
had a good look round. And first thing I've got to say is, 'Ware
snakes."

"What!" cried the boys, in a breath.

"'Ware snakes, as aforesaid, neighbours," repeated the American. "You
may depend upon it some of those gentlemen came creeping or tumbling
down from the flats above, found the premises convenient, and are living
with large families up in some of these houses."

These words had a strange effect upon the listeners. It was as if all
the interest in the place had been crashed out; all desire to explore
the wonders of this old city of the past had died away on the instant.
As for the boys, their adventures in the desert came back, and clearly
standing out were the creeping and writhing poisonous reptiles whose
stroke meant a horrible death, lurking ready for them wherever they
turned: and a shudder ran through them as if they had just been swept by
some icy wind.

Then the doctor spoke.

"That's a horrible notion of yours, Griggs," he said; "but, after all,
it is only a guess: there may not be a reptile here."

"So much the better for us, sir," cried the American cheerily; "but all
the same I say it once more--'Ware snakes."

"Yes: you all have a shot-cartridge ready?" said the doctor.

"Yes," came back--one word, and everybody unslung his double piece.

"The mules," said the doctor then--"we must not have them bitten."

"They'll be pretty safe where they are grazing," said Griggs coolly.
"Rattlesnakes don't care for places like that. It's in the stony sandy
bits where they can get the full heat of the sun that there is most
risk."

"Yes," said the doctor thoughtfully; "perhaps we might leave them as
they are."

"And pick our way slowly and carefully, doctor. Shall I go first?"

"I don't like setting you always where there is most danger," replied
the doctor.

"None for me here," replied Griggs. "It's my poor mustang who has to
run the risk; but I'll try and save him all I can."

"How?"

"Well, I've a sort of idea that I can manage it this way," replied the
American, re-slinging his rifle and taking out his strong keen-edged
hunting-knife, after dismounting and throwing his rein upon the ground
over his pony's head. The sturdy little creature stood gazing at it, as
if full of the belief that the rein held it fast to a peg driven firmly
into the ground, and never attempting to move, while its master step