by Tim Sherratt

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Early this century in the Victorian country town of Terang, the young son of a local bank manager was often seen wandering alone through the countryside, on the look-out for beetles to add to his collection. One of his treasured possessions was a book on Australian insects, in which he carefully recorded his own observations and sketches. Today that book is preserved at the University of Melbourne along with a large collection of notes, papers and photographs that tell the story of one of Australia's greatest scientists, Macfarlane Burnet.

Macfarlane Burnet never lost his fascination with the natural world, and inspired by the hero of his childhood, Charles Darwin, he sought for the rest of his life to throw some light on its underlying mechanisms. His curiousity carried him from beetle-hunting to a Nobel Prize!

Australia's international reputation for medical research is founded on the work of institutions like the Walter and Eliza Hall Institute in Melbourne. Burnet was Director of the Institute from 1944 to 1965, at a time of crucial developments in the fields of virology and immunology. He was a "hands-on" Director who always enjoyed work at the laboratory bench. From the 1930s, through the '40s and 50s he studied a range of viral diseases such as psittacosis, "Q fever", poliomyelitis and influenza. Burnet's life-long interest in ecology encouraged him to concentrate not just on the body's response to viral attack, but on the way in which these parasites survived in the natural world.

Throughout his research career, Burnet used an experimental technique he had learnt while working at the National Institute of Medical Research in London in the 1930s. An opening was made in the shell of an egg, and a sample of the virus being studied was injected into the membrane that surrounded the chick embryo. In these conditions, most viruses multiplied, allowing closer study. While modern labs are crammed with sophisticated apparatus, Burnet's main research tools were the egg and the microscope.

Macfarlane Burnet demonstrating his egg innoculation technique at the University of Wisconsin, 1952.

Burnet was a lateral thinker, inspired not just by his experimental work, but also by his wide-reading in many related fields of biology. In the 1950s, his interest shifted towards immunology and the way in which antibodies are produced. In mulling over the relevant literature he predicted that an organism would not produce antibodies to fight a "foreign" cell (or antigen) if it had been exposed to the antigen while the organism was in its embryo phase. The organism would not recognize the introduced cells as "foreign". This concept of "immunological tolerance" was confirmed by experiments conducted by Peter Medawar in England, and in 1960, Burnet and Medawar shared the Nobel Prize for Physiology or Medicine. This insight has been of vital importance in the field of organ transplantation.

But the work that Burnet regarded as his most important contribution to biology was his development of the clonal selection theory of acquired immunity. This theory, which sought to explain how animals could produce such a wide variety of antibodies, opened up vast new areas of research.

Typically, Burnet published his first account of the clonal selection theory in an Australian scientific journal. He strongly believed in encouraging scientific research in this country, and was not afraid to apply his scientific knowledge to broader social and political questions. The boy with the beetles became an example to all Australians - scientific greatness did not just come from overseas, it could be born here, even in a small country town like Terang.