The clump of slowly moving men reached the reclining cow. They pulled up stakes which surrounded her, and coiled up wire or cordage which had made the stakes into a fence. They prodded the animal. Presently it lurched to its feet and swung its head about foolishly. They drove it toward the Med Ship. Fifty yards away they stopped, and the outside microphones brought the sound of their voices muttering. By then Calhoun had seen their faces. Four of the six were bearded. The other two were young men. On most worlds men prided themselves that they needed to shave, but few of them omitted the practice. These six moved hastily away, though the two younger ones turned often to look back. The cow, deserted, stumbled to a reclining position. It lay down, staring stupidly about. It rested its head on the ground. "I go out now, eh?" asked Calhoun mildly. "_We're watching you!_" grated the spacephone speaker. Calhoun glanced at the outside temperature indicator and added a garment. He put a blaster in his pocket. He went out the exit port. * * * * * The air was bitter cold, after two months in a heat-metered ship, but Calhoun did not feel cold. It took him seconds to understand why. It was that the ground was warm. Radiant heat kept him comfortable, though the air was icy. Heat elements underground must draw power from somewhere--the grid's tapping of the ionosphere--and heated this pasture from underneath so forage plants could grow here. They did. The cattle fed on them. There would be hydroponic gardens somewhere else, probably underground. They would supply vegetable food in greater quantity. But in the nature of things human beings had to have animal food in a cold climate. Calhoun went across the pasture with the frowning snowy mountains all about. He regarded the reclining beast with an almost humorous attention. He did not know anything about the special diseases of domestic animals. He had only the knowledge required of a Med Ship man. But that should be adequate. The tense voice had said that this beast had been "dumped," to "wipe out" the local herd. So there would be infection and there would be some infective agent. He painstakingly took samples of blood and saliva. In a ruminant, certainly, any digestive-tract infection should show up in the saliva. He reflected that he did not know the normal bovine temperature, so he couldn't check it. Nor the respiration. But the Interstellar Medical Service was not often called on to treat ailing cows. Back in the ship he diluted his samples and put droplets in the usual nutrient solutions. He sealed up droplets in those tiny slides which allow a culture to be examined as it grows. His microscope, of course, allowed of inspection under light of any wave length desired, and so yielded information by the frequency of the light which gave clearest images of different features of microörganisms.