Abstract
Note 41 (p. 1556) of the article "How nature builds the pigments of life: The conquest of vitamin B12" by Alan R. Battersby (10 June, p. 1551) was incorrect as stated. The correct note should have read, "The possibility should be borne in mind that precorrin-3B (15) is initially generated as the δ-lactone (to C-20) but that, on keeping after release from the enzyme, it rearranges to the γ-lactone (to C-1)."
