Stepping-stones to One-step Growth: Frank Macfarlane Burnet's Role in Elucidating the Viral Nature of the Bacteriophages

Abstract

The demonstration of the one-step growth pattern of the bacteriophages is generally regarded as the key evidence that bacteriophages were viruses rather than enzymes of bacterial origin, a matter of considerable debate among scientists since the bacteriophage was first described in 1917. While the credit for this demonstration is usually accorded to a 1939 paper on phage growth by Emory Ellis and Max Delbr�ck, closer scrutiny of phage research conducted in the intervening two decades reveals that these papers did not present a new idea, but rather extended and refined a line of investigation about the phages that had its conceptual antecedents in the earlier work. Of particular note is the work of the Australian, Frank Macfarlane Burnet, during the late 1920s and early 1930s. Burnet's work also furnished other important reasons besides one-step growth—derived from experiments on lysogeny—for favouring the virus theoryand discarding the enzyme theory of phage. This paper examines Burnet's contributions towards understanding of the nature of phage and makes the case that it was a tacit acceptance of the evidence and arguments that he presented that allowed Ellis and Delbr�ck to make assumptions about the bacteriophage, presented as fact in their papers.