Professor.

"They are the cypress knees. In reality they are a sort of root of the tree itself. They make great hiding places for all sorts of reptiles and small animals, and they are the finest obstacles in the world to fall over."

"I should think the horses would break their legs over them," said Tad.

"A horse unfamiliar with travel in the swamp would do so. But you will find your animals very wise. They know the game down here, though up in the Rockies they undoubtedly would break their own necks and those of their riders as well."

"Every man and beast to his trade," observed the Professor reflectively.

Billy Lilly agreed with a long nod.

"Ichabod, bring in an armful of cane so the gentlemen may see it," he directed.

The sticks that Ichabod fetched resembled bamboo more than anything the boys ever had seen. These canes they found to be hollow, having no pith, being divided on the inside every few inches into sections.

"As I have already said," continued the guide, "the canebrake stretches along slight rises of ground for miles and miles, forming a very striking feature. The canes stand so thickly that they crowd out other growths and make fine hiding places for wild animals and reptiles. They stand in what might be called ranks, each but a few inches from its companion, extending to a height of fifteen or twenty feet, straight and tall."

"They should make fine fishpoles," said Tad.

"They do. They are used for that purpose. The leaves commence about two-thirds the height of the plant, and the peculiar feature of the leaves is that they seem to grow right out of the stalk."

"The cypress trees appear to be very tall here," said Professor Zepplin.

"Yes, they are. They are said to be rivaled in size and height only by some of the red gums and white oaks. In towering majesty they are really unsurpassed by any tree in the eastern forests. The redwoods of the Sierras, of course, can't be beaten by anything else in this country. There are thousands of acres of cypress and cane down here, and for a place in which to get lost the canebrake has no equal. You don't want to get lost in this forest, young gentlemen."

"We don't intend to," answered Rector.

"If we did it would not be the first time that we have lost our way," laughed Tad.

"Yes, Tad and I got lost up in the Maine woods. I never had so much fun in my life," piped Stacy. "But then there weren't any creeping things up there. I guess I'll go to bed. I'm sleepy."

"It is time we all turned in," agreed the Professor.

But there was not much sleep for the Pony Rider Boys for a long time. The unfamiliar noises of this suffocating swamp, the buzzing of the mosquitoes fighting to get into the tents, but driven back by the smoke, kept sleep away also, except in the case of Stacy Brown who began snoring almost as soon as he touched his bed.

A weird hooting and yelling that seemed to come from every direction at once brought the boys to a sitting posture about an hour after they had turned in.

"Good gracious, what's that?" demanded Ned.

"I don't know," answered Tad. "It isn't like anything I ever heard. I guess it must be some kind of wild animal."

"Those are barred owls," called the guide from the adjoining tent. "I thought their racket would wake you boys up. But you will get used to them."

"Do they howl all night?" asked Tad.

"Yes, usually, and sometimes in the day as well."

"I see our finish so far as sleep is concerned. But I am going to sleep just the same," growled Chunky.

Late in the night the campers succeeded in getting to sleep. The fire died down and the mosquitoes at last reached their victims. Stacy was the first to be awakened by the pests. He slapped and growled, and growled and slapped; then after a time he got up quietly, piling the bundle of cane on the fire, and placing heavier wood on top of that. Then, well satisfied with having done his duty, the fat boy went back to bed. But Stacy had laid the foundation for a lot of trouble that would arouse the entire camp ere many more minutes had passed.

The trouble came with a bang, with a report that sounded as if the camp had been blown up, accompanied by the yells of the boys as fire and burning sticks were hurled into the little tents.

CHAPTER IV

NATURE BLOWS OUT A FUSE

"We've blown out a fuse!" yelled Tad.

"Shut off the current!" cried Ned Rector.

"I'm shot, I'm shot!" howled the fat boy, leaping out into the open, as had Rector and Walter. "Help! Help!"

"Get back!" shouted Tad. "Don't go out there barefooted. Don't—"

Bang! Bang! Bang! The explosions became so rapid that the boys could not have counted them had they desired to do so.

A dull red glow showed in two of the tents.

"We are on fire!" yelled Butler. "Use your blankets. Stamp it out!"

Tad did not take his own advice not to step out in bare feet. He sped swiftly to his pony, and, grabbing a heavy blanket, raced back and into his own tent where, by this time, the flames had started up briskly. Throwing the blanket on the flames, Tad trod up and down, dancing a jig as he sought to beat out the flames. His quick work smothered them in short order, but at the end the boy's feet were swollen and blistered.

The guide had not been idle all this time; he had used the same tactics as had Tad, assisted by Rector, while Stacy Brown was dancing up and down yelling "Fire!" at the top of his voice.

"Stop calling for the firemen and go to work," ordered Tad. "The firemen can't hear you."

"They would be deaf if they couldn't," answered Ned from the adjoining tent. "What do you think you are yelling about, anyway?"

"Fire, fire!"

"You are slower than cream on a cold day," laughed Tad. "The fire is out."

"Then if there's nothing else to do will someone please tell me what blew up?" asked Ned.

"That is what I should like to know," nodded Tad.

"Why, the campfire blew up," Stacy informed them.

"We know that, but what caused it?"

"I—I don't know unless you fellows threw in some cartridges," replied Chunky.

"Cartridges!" exploded Ned. "Don't you think we have better use for our ammunition?"

"Guide, what is the meaning of this?" questioned the Professor.

"We will find out. I am somewhat curious myself. Ah!"

"What have you found?" asked Tad, springing into the tent where Lilly was pawing over some sticks that had fallen inside.

Lilly handed a stick of cane to Tad, who observed that the stalk had been blown out as if from an interior explosion.

"I don't understand, Mr. Lilly."

"Some of that cane got in the fire and blew up."

"Why, I never heard of such a thing," wondered Tad.

"Yes, it is quite common. This stuff is very combustible when dry. When in that condition, and the hot air is confined in the hollow sections, there is sure to be an explosion and loud one, too. That is what happened here tonight."

"Did you put cane on the fire, Mr. Lilly?"

"No, I didn't. Ichabod, did you?"

"No, sah, Ah doan' put no cane on dat fiah, sah. Ah reckons Ah know'd bettah dan to do a thing like dat, sah. Ah suah does."

"Hm-m-m!" mused the guide reflectively. "Any of you boys put cane on the fire?"

No one answered. Tad shot a keen glance at Stacy who was standing at the opening of his tent.

"Well, what have you to say for yourself, young man?" demanded Tad.

"I? Nothing," answered the fat boy.

"That was a nice trick to play on us when we were sleeping so soundly, now wasn't it?" demanded Tad.

"I—I didn't know the stuff would go off like a gun. I—I—"

"We might have known who did it," chuckled Rector.

"I am glad you admit it, Stacy," said Tad with a grin. "Better to make a clean breast right at the beginning. You know we are sure to find you out, no matter how cute