She smiled as she leaned against him. "You weren't as vague as that, the night in the hospital room. I seem to remember a few other things you said. And did. You can't claim you're completely indifferent to me, Brion Brandd. So I'm only asking you what any outspoken Anvharian girl would. Where do we go from here? Get married?" There was a definite pleasure in holding her slight body in his arms and feeling her hair against his cheek. They both sensed it, and this awareness made his words sound that much more ugly. "Lea--darling! You know how important you are to me--but you certainly realize that we could never get married." Her body stiffened and she tore herself away from him. "Why, you great, fat, egotistical slab of meat! What do you mean by that? I like you, Lea, we have plenty of fun and games together, but surely you realize that you aren't the kind of girl one takes home to mother!" "Lea, hold on," he said. "You know better than to say a thing like that. What I said has nothing to do with how I feel towards you. But marriage means children, and you are biologist enough to know about Earth's genes--" "Intolerant yokel!" she cried, slapping his face. He didn't move or attempt to stop her. "I expected better from you, with all your pretensions of understanding. But all you can think of are the horror stories about the worn-out genes of Earth. You're the same as every other big, strapping bigot from the frontier planets. I know how you look down on our small size, our allergies and haemophilia and all the other weaknesses that have been bred back and preserved by the race. You hate--" "But that's not what I meant at all," he interrupted, shocked, his voice drowning hers out. "Yours are the strong genes, the viable strains--_mine_ are the deadly ones. A child of mine would kill itself and you in a natural birth, if it managed to live to term. You're forgetting that you are the original homo sapiens. I'm a recent mutation." Lea was frozen by his words. They revealed a truth she had known, but would never permit herself to consider. "Earth is home, the planet where mankind developed," he said. "The last few thousand years you may have been breeding weaknesses back into the genetic pool. But that's nothing compared to the hundred millions of years that it took to develop man. How many newborn babies live to be a year of age on Earth?" "Why ... almost all of them. A fraction of one per cent die each year--I can't recall exactly how many." "Earth is home," he said again gently. "When men leave home they can adapt to different planets, but a price must be paid. A terrible price is in dead infants. The successful mutations live, the failures die. Natural selection is a brutally simple affair. When you look at me, you see a success. I have a sister--a success too. Yet my mother had six other children who died when they were still babies. And several others that never came to term. You know about these things, don't you, Lea?"