“Yes, that’s where I was. A man did not notice at first when only a few of these germs got into his body. But each germ broke in half and became two germs, and they kept doing this very rapidly so that in a short time there were many millions of them in the body. Then the man was sick. He had a disease, and the disease was named after the kind of a germ that was in him. It might be measles, it might be influenza, it might be yellow fever; it might be any of thousands and thousands of kinds of diseases.