Monk scratched his bullet of a head. "But, Doc, how do you account for these critters not changin’ through the ages, like they did in the outer world?"
"Evolution," Doc smiled.
"But evolution is a changing — "
"Not necessarily," Doc corrected. "Evolution is a change in animals and plants and so on, as I comprehend it. But those changes are caused by slowly altering surroundings. For example, if an animal lives in a warm country, its fur will be light, or it may have no fur at all. But if the country turns cold, the animal must grow a heavy coat, or perish. The acquiring of that fur coat is evolution.
"Conditions here in this crater have remained exactly as they were ages ago. The air is warm. There is a great deal of rain. The luxuriant plant growth makes food plentiful. Probably the seasons down here are alike the year around.
"So the prehistoric animals trapped here experienced no necessity for changing themselves to fit altered conditions, because conditions did not alter."
"That sounds reasonable," Monk admitted.
After this, silence fell. It was a somber quiet. They were thinking of Renny. They believed him dead, on the evidence of what they had seen — his hat and the gore surrounding it.
"We’d better be moving," Doc said at last. "First, we will visit the neighborhood of the hot mud lake, on the chance some supplies might have spilled out of our plane. In case you haven’t noticed it, we’re practically out of ammunition."
The others hastily examined their guns. They found only a few cartridges in each weapon. Monk, naturally the most reckless, had but four cartridges left.
"Throw the lever which changes your guns to single-shot operation," Doc directed. "We’ve got to count every bullet. Although the weapons are virtually useless against these prehistoric monsters, they will be effective upon Kar."
"Kar!" Ham clipped. "I had nearly forgotten that devil! Have you noted any signs of him, Doc?"
"Not yet. But we are not giving up our pursuit. Not even these big dinosaurs can keep us from Kar."
THEY visited the hot mud lake. So terrific was the heat of the lavalike stuff that they could not approach within yards. Too, they dreaded a sudden eruption, such as had been caused by the plane plunging into the lake.
Such geyser displays apparently came often. Great splatters of mud, now cooled, decorated the steep slope for some distance below the hot lake.
"Imagine one of them droppin’ on the back of your neck!" Monk mumbled.
"Better still, imagine what would happen to the crater floor if this broke!" Ham pointed at the lavalike dike retaining wall which confined the horseshoe-shaped body of super-heated, jellylike mud well upon the crater side.
"It would be too bad on a pig, if he happened to be down on the crater bottom, huh?" Monk suggested. Then he watched Ham’s features assume the inevitable flush of ire.
They found no speck of equipment from the plane. The craft was hopelessly gone.
To show there was no chance of salvaging it, Doc cast a small chunk of wood out on the crusted lake surface.
So hot was the crust that the wood smoldered and quickly burst into flame!
"Golly!" muttered Monk. "Let’s get out of here before that thing takes a notion to cut up!"
"We shall skirt the crater," Doc decided. "You notice the larger vegetation grows near the edges. In the center is a series of small streams. These bodies of water run sluggishly, and are hardly more than elongated bog holes."
"How about lighting a fire and getting some breakfast?" suggested the taxidermist, Oliver Wording Bittman.
Bittman had indeed regained much of his nerve. But it was with a patent effort that he was striving to maintain the standard of calmness before peril set by Doc and his men.
"No fire," Doc replied. "It might show Kar our whereabouts, if he is in the crater. Anyway, we have nothing to cook."
"The breakfast part of his idea still sounds good to me," spoke up Long Tom. "What do we eat, Doc?"
"I’ll try to find something," Doc smiled.
They betook themselves from the vicinity of the mud lake.
"Quite a climb!" Ham puffed as they descended the steep slope.
Ham, amazingly enough, had retained his sword cane through all the excitement of the parachute leap and the horror of the ensuing night. He was seldom without that secret blade. But, although it was mightily effective upon human opponents, it was virtually useless against the giant dinosaurs. The tempered blade would snap before it could be forced through one of the thick, wood-hard hides.
However, Ham very soon got a chance to use his sword cane.
An animal about the size of a large calf suddenly bounded up before them. It had four spongy looking antlers, two in the usual spot atop the head, the other pair down below the eyes. It had a cloven hoof and looked edible.
With a swift spring that would have been a credit to even Doc’s brawny form, Ham ran the strange animal through with his sword cane.
"We eat!" he grinned.
"I HAVE an idea how we can build a fire without the smoke being noticed," Doc offered. He had suddenly discovered he was hungry. "We’ll kindle a blaze near one of these streams of boiling water from which steam arises."
"Talk about necessity being the mother of ideas!" Monk grinned.
They kindled a fire, although experiencing difficulty with wet wood. Too, another sudden deluge of rain nearly put out the flames. But at length they had their breakfast cooking.
"What are we eatin’?" inquired Monk.
"A primitive type of deer," decided Johnny, the geologist.
By dipping a corner of his handkerchief into the boiling stream beside which they had built their fire, then permitting the wet cloth to cool and tasting it, Doc ascertained the water was drinkable, although it had a saline quality.
He proceeded to boil a hunk of the primitive deer in the natural caldron.
"I did that once in Yellowstone Park," said Ham.
Doc and his men kept an alert watch for danger. They were not disturbed. The meat was palatable, but had a pronounced grassy taste.
It was a sober meal, what with the thought of Renny’s possible fate.
"The insects are interesting," remarked Long Tom. "There seem to be few butterflies, moths, bees, wasps or ants. But there’s plenty of dragonflies, bugs, and beetles."
"The insects you see are the less complex types, for the most part," Doc explained. "They aren’t quite developed enough to make cocoons or gather honey. They came first in the course of evolution."
Because the great warmth within the crater would not permit them to keep meat fresh even until the next meal time, they discarded the remainder of their primitive deer. They quitted the vicinity.
"We will now go ahead with our circling of the pit," Doc said. "There may be a path by which a climber as agile as a man might depart."
Monk let out a displeased rumble. "Ugh! You mean to say we may be stuck in here, Doc?"
"Did you notice a spot where you could climb out?"
"No-o-o," Monk admitted uneasily.
Traversing some little distance, they reached a particularly tall shrub. Monk climbed this to look around. He had no more than reached the sprawling top when his excited call came down to Doc and the others.
"Smoke! I see a fire!"
Doc ran up to Monk’s side with the agility of a squirrel.
Two or three miles distant across the crater bed, smoke curled from the jungle.
"Sure it isn’t steam?" Ham inquired skeptically from the ground.
"Not a chance," Doc replied. "It’s darker than steam."
"And I just saw a burning ember, apparently a leaf, in the smoke!" Monk added.
He and Doc clambered down to the ground.
One word was upon the lips of everybody. "Kar! You think it is Kar’s fire?"