From 1958 to 1965 , he was a Professor and Head of Pathological Physiology .
From 1953 to 1956 , he was an Assistant Professor in the Department of Bacteriology at the Ontario Veterinary College .
From 1958 to 1965 , Assistant Professor was a Assistant Professor and Head of Pathological Physiology .
From 1953 to 1956 , he was an Assistant Professor in the Department of Bacteriology at the Ontario Veterinary College .