l anthropoids, cousins to the monkeys of Earth, scampered
from limb to limb, screaming at the invaders of their jungle home.
Smooth-furred animals that looked like deer, their horns curling
overhead, scampered about the cadets like puppies, nuzzling them,
nipping at their heels playfully, and barking as though in laughter when
Astro roared at them for getting in the way.

But there were dangerous creatures in the jungle too; the beautiful but
deadly poisonous brush snakes that lurked unseen in the varicolored
foliage, striking out at anything that passed; animals resembling
chipmunks with enlarged razor-sharp fangs, whose craving for raw meat
was so great that they would attack an animal ten times its size;
lizards the size of elephants with scales like armor plate that rooted
in swampy ground for their food, but which would attack any intruder,
charging with amazing speed, their three horns poised; and, finally,
there were the monsters of Venus--giant beasts whose weights were
measured in tons, ruled over by the most horrible of them all--the
tyrannosaurus.

Fights to death between the jungle creatures were common sights for the
boys during their march. They saw a weird soundless fight between a
forty-foot snake and a giant vulture with talons nearly two feet across
and a beak resembling a mammoth nutcracker. The vulture won,
methodically cutting the reptile's body into sections, its beak slicing
through the snake as easily as a knife going through butter.

More than once Astro spotted a dangerous creature, and telling Roger and
Tom to stand back, he would level his shock rifle and blast it.

So far they had seen nothing of their prey--the tyrannosaurus. Tracks
around the steaming swamps were as close as they had come. Once, late in
the evening of the second day they caught a fleeting glimpse of a
plant-eating brontosaurus lumbering through the brush.

All three of the boys had found it difficult to sleep in the jungle. The
first two nights they had taken turns at staying on guard and tending
the campfire. Nothing had bothered them, and on the third night out,
they decided the fire would be enough to scare off the jungle animals.
It was risky, but the continual fight through the jungle underbrush had
tired the three boys to the bone and the few hours they stood guard were
sorely missed the next day, so they decided to chance it.

Roger was already asleep. Astro had just finished checking his rifle to
be ready for