Leeuwenhoek Lecture - The place of viruses in nature

Abstract

In the first Leeuwenhoek lecture last year, Sir Paul Fildes (1951) reviewed the history of microbiology. In this, the second lecture, it seems to me appropriate to take stock of our knowledge of one part of the field of microbiology, a part which is full of implications for all branches of biology. There are, as you know, very diverse views as to the nature of viruses. As you will soon discover it anyhow, I may as well confess at the outset that I believe them to be small organisms. In maintaining this, I shall derive considerable moral support from this portrait of Antony van Leeuwenhoek at my side. He was the discoverer of the little animals whose study to-day comprises the field of microbiology. I do not think he would be surprised at the existence of creatures smaller and still smaller, made visible nowadays only by means of electron-microscopy. I propose to discuss the place in nature of viruses from two points of view, which I will call the taxonomic and the ecological. First, are they animal or vegetable (or neither), and if organisms, where do they fit in in relation to other organisms? Secondly, what is their role in the interaction of one form of life with another from and with environment? I shall subsequently consider the taxonomic and ecological aspects together, in the hope of visualizing the position of viruses in the scheme of things in a way which makes some sort of sense.