"Now this is the strange thing about these germs. There were always new ones coming to live in men's bodies. Long and long and long ago, when there were only a few men in the world, there were few diseases. But as men increased and lived closely together in great cities and civilizations, new diseases arose, new kinds of germs entered their bodies. Thus were countless millions and billions of human beings killed. And the more thickly men packed together, the more terrible were the new diseases that came to be. Long before my time, in the middle ages, there was the Black Plague that swept across Europe. It swept across Europe many times. There was tuberculosis, that entered into men wherever they were thickly packed. A hundred years before my time there was the bubonic plague. And in Africa was the sleeping sickness. The bacteriologists fought all these sicknesses and destroyed them, just as you boys fight the wolves away from your goats, or squash the mosquitoes that light on you. The bacteriologists—"
"But, Granser, what is a what-you-call-it?" Edwin interrupted.
"You, Edwin, are a goatherd. Your task is to watch the goats. You know a great deal about goats. A bacteriologist watches germs. That's his task, and he knows a great deal about them. So, as I was saying, the bacteriologists fought with the germs and destroyed them—sometimes. There was leprosy, a horrible disease. A hundred years before I was born, the bacteriologists discovered the germ of leprosy. They knew all about it. They made pictures of it. I have seen those pictures. But they never found a way to kill it. But in 1984, there was the Pantoblast Plague, a disease that broke out in a country called Brazil and that killed millions of people. But the bacteriologists found it out, and found the way to kill it, so that the Pantoblast Plague went no farther. They made what they called a serum, which they put into a man's body and which killed the pantoblast germs without killing the man. And in 1910, there was Pellagra, and also the hookworm. These were easily killed by the bacteriologists. But in 1947 there arose a new disease that had never been seen before. It got into the bodies of babies of only ten months old or less, and it made them unable to move their hands and feet, or to eat, or anything; and the bacteriologists were eleven years in discovering how to kill that particular germ and save the babies.
"In spite of all these diseases, and of all the new ones that continued to arise, there were more and more men in the world. This was because it was easy to get food. The easier it was to get food, the more men there were; the more men there were, the more thickly were they packed together on the earth; and the more thickly they were packed, the more new kinds of germs became diseases. There were warnings. Soldervetzsky, as early as 1929, told the bacteriologists that they had no guaranty against some new disease, a thousand times more deadly than any they knew, arising and killing by the hundreds of millions and even by the billion. You see, the micro-organic world remained a mystery to the end. They knew there was such a world, and that from time to time armies of new germs emerged from it to kill men.