same trilling hiss.
It was beginning to get on the nerves of the Rangers. They were getting
mad. The Pony Rider Boys felt a sense of discomfort too, though none
showed any nervousness. It was not the first time the young explorers
had passed through such an experience. Just the same they would have
preferred to be in some other locality just then.

Finally Stacy went to sleep. When he woke up with a start, he tried
to recall what had been going on when he dropped off. Then he
remembered. He had been indulging in his famous imitation of an angry
serpent. Had any of the men been awake at the moment he might have
seen the fat boy's blanket shaking as if the boy were sobbing. But
Stacy Brown was not sobbing.

It was some moments before he had subdued his merriment sufficiently
to hiss again. The hiss was unheard. Stacy opened his eyes as he saw
the captain striding into camp. He saw McKay awaken the Rangers, then
start to arouse the Pony Rider Boys. In his wonderment at the
proceeding Stacy forgot to hiss again for some time.

"Saddle up," commanded the captain sharply, but in a low tone.

The camp, so silent a few moments before, was now a scene of orderly
activity. Every man in it was packing his pony and in less than ten
minutes after the alarm had been given the men were in their saddles.
The Pony Rider Boys were full of anticipation. It looked to them as
if something were going to develop that was worth while.

Starting off in single file the men dozed in their saddles, but the
Pony Rider Boys did not. The latter were too much excited for sleep.
All at once that trilling hiss came again. Two dozing Rangers landed
on their backs in the bush. The party was in an uproar, but as
suddenly quieted by a stern word from the captain. The latter wondered
at their being followed by a rattler. It was peculiar to say the least.

Stacy hissed again. Then the boy shivered, for a heavy hand was laid
on his arm, closing over it until the fat boy yelled.

"Ouch! Let go of my arm!" he cried.

"Young man, I think I've got the rattler this time," said the stern
voice of Captain Billy McKay, as the fat boy fairly shrank within
himself.

CHAPTER XIX

SURROUNDING THE ENEMY

"What's that?" roared Dippy.

"Here's your rattler. I've been suspecting him ever since early in
the evening. This young man has been imitating a rattler's hiss and
I must say he did it mighty well."

"What's that? 'Bugs' b