Dr. Pilar leaned back in his chair and looked at the big man with interest. "Well," he said carefully, "that would all depend on what it was. If it was something really ... ah ... dangerous to the welfare of the expedition, I'd have to say something about it, I suppose, but I'm not a military officer, and minor infractions don't concern me." MacNeil absorbed that "Well, sir, this ain't much, really--I ate something I shouldn't of." Pilar drew down his brows. "Stealing food, I'm afraid, would be a major offense, under the circumstances." MacNeil looked both startled and insulted. "Oh, nossir! I never swiped no food! In fact, I've been givin' my chow to my buddies." Pilar's brows lifted. He suddenly realized that the man before him looked in exceptionally good health for one who had been on a marginal diet for two weeks. "Then what _have_ you been living on?" "The monkey food, sir." "_Monkey food?_" "Yessir. Them greenish things with the purple spots. You know--them fruits you feed the monkeys on." Pilar looked at MacNeil goggle-eyed for a full thirty seconds before he burst into action. * * * * * "No, of course I won't punish him," said Colonel Fennister. "Something will have to go on the record, naturally, but I'll just restrict him to barracks for thirty days and then recommend him for light duty. But are you _sure_?" "I'm sure," said Pilar, half in wonder. Fennister glanced over at Dr. Smathers, now noticeably thinner in the face. The medic was looking over MacNeil's record. "But if that fruit kills monkeys and rats and guinea pigs, how can a _man_ eat it?" "Animals differ," said Smathers, without taking his eyes off the record sheets. He didn't amplify the statement. The colonel looked back at Pilar. "That's the trouble with test animals," Dr. Pilar said, ruffling his gray beard with a fingertip. "You take a rat, for instance. A rat can live on a diet that would kill a monkey. If there's no vitamin A in the diet, the monkey dies, but the rat makes his own vitamin A; he doesn't need to import it, you might say, since he can synthesize it in his own body. But a monkey can't. "That's just one example. There are hundreds that we know of and God alone knows how many that we haven't found yet." Fennister settled his own body more comfortably in the chair and scratched his head thoughtfully. "Then, even after a piece of alien vegetation has passed all the animal tests, you still couldn't be sure it wouldn't kill a human?" "That's right. That's why we ask for volunteers. But we haven't lost a man so far. Sometimes a volunteer will get pretty sick, but if a food passes all the other tests, you can usually depend on its not killing a human being." "I gather that this is a pretty unusual case, then?"