the animal for support. He lifted himself up and fell across the bed in exhaustion. Blood didn't circulate well in his crippled body. The animal bounded up and tried to melt itself into his body. He couldn't push it away if he wanted. He didn't want to. He stirred and got himself into a more comfortable position. He wasn't going to die.

In the morning, Bolden was awake long before the doctor came in. Kessler's face was haggard and the smile was something he assumed solely for the patient's benefit. If he could have seen what the expression looked like after filtering through the microscreen, he would have abandoned it. "I see you're holding your own," he said with hollow cheerfulness. "We're doing quite well ourselves."

"I'll bet," said Bolden. "Maybe you've got to the point where one of the antibiotics doesn't actually stimulate the growth of the microbes?"

"I was afraid you'd find it out," sighed the doctor. "We can't keep everything from you."

"You could have given me a shot of plasma and said it was a powerful new drug."

"That idea went out of medical treatment a couple of hundred years ago," said the doctor. "You'd feel worse when you failed to show improvement. Settling a planet isn't easy and the dangers aren't imaginary. You've got to be able to face facts as they come."

He peered uncertainly at Bolden. The microscreen distorted his vision, too. "We're making progress though it may not seem so to you. When a mixture of a calcium salt plus two antihistamines is added to a certain neobiotic, the result is that the microbe grows no faster than it should. Switching the ingredients here and there—maybe it ought to be a potassium salt—and the first thing you know we'll have it stopped cold."

"I doubt the effectiveness of those results," said Bolden. "In fact, I think you're on the wrong track. Try investigating the effects of neural induction."

"What are you talking about?" said the doctor, coming closer and glancing suspiciously at the lump beside Bolden. "Do you feel dizzy? Is there anything else unusual that you notice?"

"Don't shout at the patient." Bolden waggled his finger reprovingly. He was proud of the finger. He couldn't feel what he was doing, but he had control over it. "You, Kessler, should face the fact that a doctor can learn from a patient what the patient learned from the natives."

But Kessler didn't hear what he said. He was looking at the upraised hand. "You're moving almost normally," he said. "Your own immunity factor is controlling the disease."

"Sure. I've got an immunity factor," said Bolden. "The same one the natives have. Only it's not inside my body." He rested his hand on the animal beneath the covers. It never wanted to leave him. It wouldn't have to.

"I can set your mind at rest on one thing, Doctor. Natives are susceptible to the disease, too. That's why they were able to recognize I had it. They gave me the cure and told me what it was, but I was unable to see it until it was nearly too late. Here it is." He turned back the covers and the exposed animal sleeping peacefully on his legs which raised its head and licked his fingers. He felt that.

After an explanation the doctor tempered his disapproval. It was an unsanitary practice, but he had to admit that the patient was much improved. Kessler verified the state of Bolden's health by extensive use of the X-ray microscope. Reluctantly he wheeled the machine to the wall and covered it up.

"The infection is definitely receding," he said. "There are previously infected areas in which I find it difficult to locate a single microbe. What I can't understand is how it's done. According to you, the animal doesn't break the skin with its tongue and therefore nothing is released into the bloodstream. All that seems necessary is that the animal be near you." He shook his head behind the