JOE stared at the stream in terrible fascination, half expecting to see many other of the repulsive reptiles make an appearance. But if any more were there, they failed to come in sight.

“One’s enough, though,” mused Joe.

Mr. Holton motioned for Noko to lead the way. True, it promised to be a trying experience, crossing that slippery log, but the sooner over the better.

A rope was handed to each of the whites, who grasped it thankfully. The natives, however, had little need for this aid, accustomed as they were to jungle life. Even with the heavy packs, they went easily across to the other side.

Mr. Lewis and Mr. Holton also stepped across without difficulty. Bob, the next to try it, demonstrated his skill by not making a single misstep. Joe, who was last, gripped the rope a little more tightly than had the others, for he had never considered himself good at balancing.

“Take it slowly,” cautioned his father, looking on anxiously from the other side. “Don’t look at the water. It might make you dizzy.”

Joe was more than halfway across when a terrific splashing sound made him glance around impulsively. Then his expression changed, and he suddenly grew pale.

His foot was slipping—slowly, to be sure, but slipping!

Suddenly the youth gave a wild cry of fear and then went plunging into the muddy water!

There were anxious shouts from the opposite shore as Mr. Lewis and Mr. Holton pulled desperately on the rope. Bob and Noko also lent their efforts, and together the four drew Joe slowly but surely toward the bank.

“Hurry!” cried Joe frantically. “The crocodile!”

The huge reptile hesitated a moment as it gazed intently at the broken waters. Then, as though suddenly grasping what was taking place, it swung into action and swam toward Joe.

The latter was some fifty feet away, and, aided by the stout rope was swimming rapidly. But the crocodile also was moving at no slow gait!

“Quick!” shouted Mr. Lewis, pulling with all his strength. “In less than a minute it will be too late.”

He placed his section of the rope in the hands of a bearer and grasped his rifle. A second later he pulled the trigger.

Bang!

The sound of the gun was followed by a terrific threshing about as the crocodile gasped out its last breath. Then the motion ceased, and the great saurian disappeared into the dark water.

“Thank goodness!” breathed Bob.

By now Joe had reached the shore and was scrambling up the steep bank. He was a sorry-looking sight as he faced the others.

“Thought I was a goner,” he said, with a ghost of a smile. “But that rifle shot did the trick, all right.”

“It certainly did,” said Mr. Holton. “Ben never fired a more accurate shot. Strange, but it never occurred to me to use a rifle. I was only thinking of pulling harder on the rope.”

“I wasn’t sure that I could hit the crocodile,” Mr. Lewis put in. “I imagine I wasn’t any too steady after the terrific strain. But through luck, I guess, that bullet penetrated the brain.”

Joe was watersoaked to the skin, and mud was caking on his clothes.

“Better put on something dry,” advised Mr. Holton, and Noko, understanding, nodded.

“Get heap sick,” the native said, using the English he had picked up. “Um fever here. Soon come night. Then be heap cold.”

“I guess you’re right,” Joe admitted. “Then too, it doesn’t feel very pleasant with these wet clothes on.”

It did not take him long to change, and he was soon ready to continue the journey.

Noko urged that they make unusually good time from now until dark so as to get to a certain clearing before nightfall. Of course, they could have stopped and made camp at many places, but the native did not wish to do so.

As the guide had hoped, they reached the place he had in mind just as darkness was beginning to enshroud them.

During the next few minutes all worked hurriedly, so as to complete making camp before the blackness would handicap them. For night in the tropics comes quickly, there being little or no twilight.

The tents were fastened securely to the stakes, the provisions unpacked, and a roaring fire was built.

“Now for what’s coming,” grinned Bob, smacking his lips. “And am I hungry!”

Before long a tempting odor filled the air, one that was entirely new to the youths. Just what food was being prepared they could not even guess.

The taste was excellent, however, as they found a little later.

“Trust the natives to pick out what’s good,” remarked Mr. Lewis, when the meal was over. “They know of many edible wild herbs, roots, and berries that we whites have never tasted.”

Darkness had overtaken them, a darkness that was filled with mystery. From afar came some terrifying scream, uttered perhaps by a wild animal in its death struggle. Soon there came another that was even more blood curdling.

“Listen!” hissed Mr. Holton, straining his ears to make out the distant cry more distinctly.

“What is it?” inquired Joe.

“A lion,” was the answer. “He seems to be coming closer.”

“Gee. Maybe we can get a shot at his lordship,” grinned Bob, picking up his rifle.

But if the lion was near the camp he failed to cause a disturbance. Perhaps the brute had sensed that someone had invaded his domain, but had also sensed that it would be dangerous to interfere.

“What’s that over there?” demanded Bob, making out something just beyond the fire.

“Why—it looks like two red lights,” observed Joe. “And they seem to be coming closer.”

The naturalists’ eyes followed those of their sons. Then Mr. Holton reached for his rifle.

“Keep quiet,” he whispered, taking careful aim at the red “lights.”

Then he fired, the report being followed by a terrible screeching and wailing noise. With one last groan, the animal, whatever it was collapsed.

“Hurray!” yelled Joe. “Got him, Mr. Holton. But what was it?”

The victim proved to be a huge lemur, an animal that looked like a cross between a monkey and a cat. It was about three feet long and had an unusually long tail.

“But, say, Dad,” came from Bob, “where did that bullet strike? It didn’t smash his face.”

“That’s part of the trick of shooting,” laughed Mr. Lewis. “Howard saw its eyes in the darkness, and so aimed below at the body.”

The animal was carefully skinned and the skin placed in preservative. Then, this task being over, they sat idly around the fire and chatted merrily.

At frequent intervals they could hear cries of wild animals, including the trumpeting of elephants and the mournful groan of hyenas. Once they heard a horrid growl that Mr. Lewis said was made by a leopard.

Despite the clamor of the African night, Bob and Joe slept soundly and awoke the next morning greatly refreshed.

“Drink deeply of this cool air,” said Mr. Lewis, stopping for a moment at the boys’ tent. “Along towards noon, as you already know, the sun will be far too hot for comfort.”

The natives were astir, attending to the many tasks that went with breaking camp. Breakfast was at once followed by pulling up the stakes, folding the tents, and loading the provisions and other articles in their proper places on the backs of the bearers.

Soon the expedition was again penetrating deep into the dense jungle. Although the traveling was necessarily slow, every hour saw them a little nearer the unknown Forest of Mystery.

Along towards noon Noko called a halt. It was wholly unwise to continue in the terrific noonday heat of Africa. They stopped at a little open space which was devoid of vegetation except for tall grass.

Everyone rested in the shade of a huge tree, whose branches extended out over a wide area.

Bob and Joe, however, soon tired of remaining so long in one position, and finally decided to explore the country in the immediate vicinity of the safari.

“We won’t be gone long,” remarked Bob, speaking to the naturalists. “Just want to look around a little.”

“Be careful, boys,” warned his father. “Always be prepared for dangers.”

There was a narrow trail that wound toward a little elevation not far away. Along this the youths walked, keeping their eyes open for anything unusual.

“I wouldn’t mind meeting something dangerous,” grinned Joe, gripping his rifle the tighter. “Somehow I want action.”

“Didn’t you get enough of that yesterday when you fell in that stream?” asked Bob.

“It was enough for yesterday,” returned Joe. “But this is today.”

Suddenly the chums caught sight of something that filled them with wonder.