However it was in 1944 that Avery made his legacy along with a fellow colleague at the institute. McCarty and Avery concentrated on the phenomenon of pneumococcal transformation, in which R-form (non virulent) bacteria changed into the S-form (virulent) when killed S-form Avery’s early work came to the attention of the director of the Hospital of the Rockefeller Institute for Medical Research. In 1913 he focused most of his