Benson presents, in this issue, a
personal story of the discovery of this cycle. He brings
before us the early work of Samuel Ruben and Martin
Kamen, co-discoverers of C-14, that later led to
the path of carbon in photosynthesis. David Walker
presents an essay on the discovery (during 1937–1940)
of the Hill reaction in chloroplasts that clearly showed
the biochemical separation of ‘light reactions’ from
the ‘dark reactions.’