The other dog came whining from the far corner of the field to which he had fled in terror. He was a courageous dog, but he could not face the great carnivore. He whimpered and licked the face of his mate. The biologist picked up the mangled dog and headed toward the laboratory. "You can't save her," said Hafner morosely. "She's dead." "But the pups aren't. We'll need them. The rats won't disappear merely because tigers have showed up." The head drooped limply over his arm and blood seeped into his clothing as Hafner followed him up the hill. "We've been here three months," the exec said suddenly. "The dogs have been in the fields only two. And yet the tiger was mature. How do you account for something like that?" Marin bent under the weight of the dog. Hafner never would understand his bewilderment. As a biologist, all his categories were upset. What did evolution explain? It was a history of organic life on a particular world. Beyond that world, it might not apply. Even about himself there were many things Man didn't know, dark patches in his knowledge which theory simply had to pass over. About other creatures, his ignorance was sometimes limitless. Birth was simple; it occurred on countless planets. Meek grazing creatures, fierce carnivores--the most unlikely animals gave birth to their young. It happened all the time. And the young grew up, became mature and mated. He remembered that evening in the laboratory. It was accidental--what if he had been elsewhere and not witnessed it? They would not know what little they did. He explained it carefully to Hafner. "If the survival factor is high and there's a great disparity in size, the young need not ever be young. They may be born as fully functioning adults!" * * * * * Although not at the rate it had initially set, the colony progressed. The fast crops were slowed down and a more diversified selection was planted. New buildings were constructed and the supplies that were stored in them were spread out thin, for easy inspection. The pups survived and within a year shot up to maturity. After proper training, they were released to the fields where they joined the older dogs. The battle against the rats went on; they were held in check, though the damage they caused was considerable. The original animal, unchanged in form, developed an appetite for electrical insulation. There was no protection except to keep the power on at all times. Even then there were unwelcome interruptions until the short was located and the charred carcass was removed. Vehicles were kept tightly closed or parked only in verminproof buildings. While the plague didn't increase in numbers, it couldn't be eliminated, either.