Classification of bacterial viruses: characteristics of the T1,D20 species of coli-dysentery phages.

Coliphage Ti of Demerec and Fano (1945) has been found to be closely related serologically to dysentery phage D20 of Burnet (1933). A comparative study of the properties of these two phage strains has been made in order that the distinctive characteristics of the T1,D20 species may be better defined. It is unfortunate that of a large number of enteric phages studied, these two were the only strains found to be in this serological group. Burnet had found only one other phage, strain G, to be serologically related to D20, and strain G is no longer available. This paper is one of a series devoted to the development of a systematic classification of the bacteriophages (Adams, 1953). It is hoped that such studies will indicate those taxonomic criteria which are of greatest value in phage classification.