I admitted that I had tossed him a baiting question to see how he would answer. The Senior nodded. "I know you're not stupid, Son; I had Athene give me a runback on your ancestry. But I have often been amazed at how the moderately bright and moderately well-informed-which describes no one in this happiness circle, so no one need pretend to modesty- how often such somewhat superior people have trouble coming to grips with the ancient silk-purse-and-sow's-ear problem. If heredity were not overwhelmingly more important than environment, you could teach calculus to a horse.

"In my early days it was an article of faith among a self-styled 'intellectual elite' that they could teach calculus to a horse...if they started early enough, spent enough money, supplied special tutoring, and were endlessly patient and always careful not to bruise his equine ego. They were so sincere that it seems downright ungrateful that the horse always persisted in being a horse. Especially as they were right, if 'starting early enough' is defined as a million years or more.

"But those savages will make it; they can't avoid winning. The problem in reverse is more horridly interesting. Justin, do you realize that we Howards killed off Old Terra?"

"Yes."

"Now, now, Son, you're not supposed to answer in such a way as to chop off conversation...thereby leaving us with nothing to do but get drunk and cuddle the girls."

"Swell!" Obadiah-Galahad shouted. "Let's!" He had Minerva with him at that moment; he grabbed her and flipped her over facing him. "Little whatever-your-name-is, do you have any last words?"

"Yes."

"'Yes' what?"

"Just 'Yes.' That's my last word."

"Galahad," said Ishtar, "if you're going to rape Minerva, drag her back of the fountain. I want to hear what Justin means by that."

"How can I rape her when she won't fight?" he complained.

"You've always been able to solve that problem. But do it quietly. Justin, I find myself shocked. It seems to me that we've been quite generous in supplying Old Home Terra with new technologies-and there's not much else we can give them. Didn't the last migrant transport come back only half loaded?"

"I'll answer it," Lazarus growled. "Justin might pretty it up. Not all the Howards. Two. Andy Libby provided the weapon; I delivered the coup de grace. Space travel killed Earth."

Ishtar looked troubled. "Grandfather, I don't understand."

"She calls me that when I've been naughty," the Senior confided to me. "It's her way of spanking me. Ish darling, you are young and sweet and have spent your life studying biology, not history. Earth was doomed in any case; space travel just hurried it along. By 2012 it wasn't fit to live on-so I spent the next century elsewhere, although the other real estate in the Solar System is far from attractive. Missed seeing Europe destroyed, missed a nasty dictatorship in my home country. Came back when things appeared to be tolerable, found that they weren't-and that's when the Howards had to run for it.

"But space travel can't ease the pressure on a planet grown too crowded, not even with today's ships and probably not with any future ships-because stupid people won't leave the slopes of their home volcano even when it starts to smoke and rumble. What space travel does do is drain off the best brains: those smart enough to see a catastrophe before it happens and with the guts to pay the price-abandon home, wealth, friends, relatives, everything-and go. That's a tiny fraction of one percent. But that's enough."

"It's the bell curve again," I said to Ishtar. "If-as Lazarus thinks, and statistics back him up-every migration comes primarily from the right-hand end of the normal-incidence curve of human ability, then this acts as a sorting device whereby the new planet will show a bell curve with a much higher intelligence norm than the population it came from...and the old planet will average almost imperceptibly stupider."

"Imperceptible except for one thing!" Lazarus objected.

"That tiny fraction that hardly shows statistically is the brain. I recall a country that lost a key war by chasing out a mere half dozen geniuses. Most people can't think, most of the remainder won't think, the small fraction who do think mostly can't do it very well. The extremely tiny fraction who think regularly, accurately, creatively, and without self-delusion-in the long run these are the only people who count and they are the very ones who migrate when it is physically possible to do so.

"As Justin said, statistically it hardly shows. But qualitatively it makes all the difference. Chop off a chicken's head and it doesn't die at once; it flops around more energetically than ever. For a while. Then it dies.

"That's what space travel did to Earth: chopped its head off. For two thousand years its best brains have been migrating. What's left is flopping harder than ever...to no purpose and will die that much sooner. Soon, I think. I don't feel guilty about it; I see no sin in those smart enough to escape escaping if they can-and the death rattle of Earth was clear and strong back in the twentieth century, Earth reckoning, when I was a young man and space travel had barely started-not even started in interstellar terms. It took two more centuries and then some to get it rolling. Can't count the first migration of the Howards; it was involuntary, and they weren't the best brains.

"The later Howard migration to Secundus was more important; it shook out some of the dullards, left them behind. The non-Howard migrations were even more important. I've often wondered what would have happened if there had been no political restraints against migrating from China; the few Chinese who did reach the stars seem always to be winners, I suspect that the Chinese average smarter than the rest of Earth's spawn.

"Not that slant of eye or color of skin matters today, or even matters at the moment of truth. One of the early Howards was Robert C. M. Lee, of Richmond, Virginia-anybody know what his name was originally?"

"I do," I answered.

"Of course you do, Justin, so keep quiet-and that includes you, Athene. Anyone else?"

No one answered; Lazarus went on: "His birth name was Lee Choy Moo; he was born in Singapore, and his parents came from Canton in China-and of the people in the 'New Frontiers' he was a mathematician second only to Andy Libby."

"Goodness!" said Hamadryad. "Fm descended from him- but I didn't know he was a great mathematician."

"Did you know he was Chinese?'

"Lazarus, Fm not sure what 'Chinese' means; I haven't studied much terrestrial history. Isn't it a religion? Like 'Jewish'?"

"Not exactly, dear. The point is that it no longer matters. Just as few know and no one cares that the famous Zaccur Barstow, my partner in crime, was a quarter Negro. Does that word mean anything to you, Hamadarling? Not a religion."

"The word means 'black,' so I assume that one of his grandparents was from Africa."

"Which shows what comes of assuming anything on one datum. Two of Zack's grandparents, both mulatto, came from Los Angeles in my homeland. Since my line mixed with his a long time back, probably any of you can claim African ancestry. Which is statistically equivalent to claiming descent from Charlemagne. I've gone far afield, and it is time we picked a new Stimulator and a new Respondent. Space travel ruined old Earth-that's one viewpoint. The other side of the coin, happier and more important in the long run, is that it improved the breed. Probably saved it as well but 'improved' is certain. Homo sapiens is now not only far more numerous than he ever was on Earth; he is a better, smarter, more efficient animal in every measurable fashion. Further this Respondent sayeth not; somebody else grab it. Lazi, quit trying to tickle me and go bother Galahad; Minerva needs a rest."