Colonies of such resistant strains have haloes of growth around them when plated on sensitive strains in the presence of norleucine. A mutant (strain P-76-2) selected as a norleucine-resistant strain ...
76.6 x 76.3 cm (30 1/8 x 30 in.) Signed, Signed and numbered 30/ in pencil on the reverse (there were also 18 artist's proofs), published by The Paragon Press, London, framed.