AbstractIn the space of three years–from 1962 to 1964 – the proposition that chloroplasts contain their own DNA made the transition from being a controversial hypothesis to an accepted dogma. The crucial evidence came from biochemical analyses of the organelles themselves and from cytological studies. These discoveries revolutionized our views on the distribution of genetic information within the cell, and gave rise to the vigorous new field of chloroplast molecular biology. It is nevertheless ironic to recall that of the biochemical papers published on this topic in 1962–64, the one which was probably the most influential in creating the new paradigm was in fact quite wrong, and attributed to the chloroplast, DNA species which did not in reality belong to this organelle a