The Virus Hunters The mouth of the Amazon River has long been a starting place for hunters going to the jungles of Brazil. In recent years it has been, too, the headquarters for a middle-aged American couple who hunt the smallest living things and perhaps the most deadly viruses. Dr Causey and his wife have discovered more new types and more old ones in new places than all of the other search teams. Dr. Causey insists that the couple's success is due more to the number of viruses in the forests of the Amazon than to the skill he and his wife have developed during their eighteen years of work in Brazil. 'We have found the loveliest diseases fight in our backyard,' he told me one day as we walked through a light rain along a jungle trail. 'Oh, these viruses are here all fight. There is in the jungle a great pool of disease which is carried in the blood of animals and birds. Some of the diseases can be caught by people. It may be that we shall find that the jungle is a great center of virus disease and that it overflows from here to other parts of the world. It may be that birds carry the viruses to far countries. It may be that some viruses which presently reproduce in man without making him ill, may change and become deadly to him. 'Viruses waiting for a disease,' they are sometimes called. This is just an idea, you understand. We do not know, but it is important that we find out, and the first step in finding out is to learn what viruses there are in the jungles.' There is a Brazilian story about the beginning of the world which goes: 'When God was making the world he tried to keep everything in balance. When he made a desert, he provided it with some green places. When he made a land that was beautiful, he gave it storms and other terrible things caused by the weather, where the earth was rich below the surface, it was also made hard to live on, where the land could be farmed, the weather was made too hot or too cold or too dry. Where there was enough water, God made it so that there should sometimes be too much water. 'But in one place God made a land that was rich, where everything grew easily, where it was not too hot and certainly not too cold, where animals were plentiful and fruit hung from the trees all the year round.' 'The angels looked at this loveliness and were jealous of man. They asked God if this was not too beautiful, too much like heaven, this valley of the Amazon.' And God said, 'True, this land looks like heaven, but wait until you see what happens to man when he tries to live in it.' When Dr. Causey said, 'We have found the loveliest diseases right in our backyard,' he meant ______.