Anywhen by James Blish Page B

right. The cubs are born as far as the savages are concerned, but medically they won't be born for another month yet."
    "What do you mean?" Roche said. "Dammit, Clyde, you'll pay for this. If you'd spoken earlier—"
    "I spoke soon enough," Doc Bixby said, but he retreated a little from the savagery in Roche's voice. "The cubs are embryologically immature, that's all. From the point of view of development, they're still foetuses. They seem to get born as soon as they can control their muscles, and then they crawl up into the dam's arms to be nursed the rest of the way to `term'—like marsupials on Earth. I knew it would be that way as soon as I realized that these creatures had to have two functional pelvic gir dies. If those bones are to be in balance well enough to serve as fulcrums for two pairs of hind limbs—and you can see that that's what the original situation was by looking at the 'horses'—then neither of them could simultaneously be flexible enough to pass a full-term cub. It was much more likely that they littered very early and maintained the whelps outside the womb until they reached term. They probably have many more children than they ever manage to raise; the weak ones just don't manage to make it into the nursing arms, and fall off to die. A good system for selecting out weak sisters—brutal for the spawn, but kind to the race. That's evolution for you every time."
    "Very like the marsupials," Roche said in a flat, quiet voice.
    "Yes, just as I said."
    "What did evolution ever do for the marsupials? Opossums and kangaroos are notably inefficient animals. They've shucked off their weak sisters that way for millions of years, and still they're no better equipped to survive than they ever were! But never mind, we can't change that. What I want to know is, can we still immunize these cubs? Are they still unborn in that sense? In short, Clyde, now that your practical joke is over—is there still time? I've made promises. Can I keep them?"
    "I didn't . . . Sure you can. I took blood samples and ran antibody titers on one of the cubs when I first discovered this. They're naturally immune until they're `born'; they're getting the appropriate beta-globulins from their mothers' milk. You can save them."
    "No thanks to you," Roche said in a raw, ragged whisper.
    "No," Bixby said. Abruptly, he looked quite haggard. "I suppose not. All I can say is, I would have spoken bef ore you promised anything if it had really been too late.
    But there is still time."
    In the tank, the warriors held out their children.
    It went very well after that, all things considered. By the time we left, the plague was greatly slowed down, and Roche and the computer between them were convinced that it would cease to be an important pandemic on Savannah not long after the Chisholm left. It wouldn't be exterminated, of course. Now that it had been established in so many living cells, the virus would be passed on, from generation to generation, protected in its intracellular environment from any possible concentration of antibodies circulating in the extracellular fluids of the body. But by that same token, this chronic infection would keep the antibody titers high, and prevent the virus from causing any overt illness. The immunity would stick, which was what we had sought, and what we brought about.
    It was over.
    Except that I have come up at last with what it was that had been bothering me the whole time. And it was not just a fantasm, not just a crotchet. It was real, and came crawling into my head in all its unavoidable dread and revulsion at the moment that I opened my new orders, and found that I was again assigned to be the astrogator of the Chisholm.
    At that instant, I remembered that the Conestoga wagon was the machine that brought tuberculosis to the Indians . . . and the orders say that we are on our way back to Savannah.
     

Nietzsche's book of the same title was of course the main source of this story, which won one of Judith