Understanding of biological nitrogen fixation has advanced with impressive rapidity during the last decade. As befits a developing area of Science, these advances have uncovered information and raised questions which will have, and indeed have had, repercussions in numerous other branches of science and its applications. This 'information explosion', to use one of to-day's cant idioms, was initiated by the discovery, by a group of scientists working in the Central Research laboratories of Dupont de Nemours, U. S. A., of a reproducibly active, cell-free enzyme preparation from a nitrogen-...