The doctor seized it. "Beautiful, isn't it?"
"Perhaps—taken by itself." Dan rolled up his sleeve. "See how it joins the forearm."
Crander waggled it gravely. "It coordinates perfectly. I've observed you have complete control over it. The doctor's eye, my boy. The doctor's diagnostic eye."
The other just didn't understand. "But the size—it doesn't match my arm!"
"Doesn't match?" cried the doctor. "Do you have any idea of the biological ways in which it does match? True, it may not be esthetically harmonized, but here we delve into the mysteries of the human organism, and we can hardly be striving for Botticelli bodies and Michelangelo men. First, your hand moves freely at the joint, a triumph of surgical skill." He moved the hand experimentally, to show Merrol how it was done. He dropped the hand and hurried to a screen against the wall.
Crander drew his finger across the surface and the mark remained. "You know about Rh positive and negative blood. Mixed, they can be lethal. This was discovered long ago, by someone I've forgotten. But there are other factors just as potent and far more complex."
He scribbled meaningless symbols on the screen with his finger. "Take the bone factors—three. They must be matched in even such a slight contact as a joint ... this was done. Then there are the tissue factors—four. Tendon factors—two. Nerve-splice factors—three again. After that, we move into a complex field, hormone-utilization factors—seven at the latest count and more coming up with further research.
"That's the beginning, but at the sensory organs we leave the simple stuff behind. Take the eye, for instance." Merrol leaned away because Dr. Crander seemed about to pluck one of Dan's eyes from its socket. "Surgical and growth factors involved in splicing a massive nerve bundle pass any layman's comprehension. There are no non-technical terms to describe it."
It was just as well—Merrol didn't want a lecture. He extended his arms. One was of normal length, the other longer. "Do you think you can do something with this? I don't mind variation in thickness—some of that will smooth out as I exercise—but I'd like them the same length."