Research in animals and plants is frequently 'departmentalized' and funded according to Kingdoms by granting bodies. The use of transgenes to address biological questions in all Kingdoms led us to propose to the Royal Society that fundamental and strategic studies in animals and plants involving trans genes should be presented in one meeting, rather than, as so often happens, in different scientific societies. The two-day Discussion Meeting held inJuly 1992, and reported here provided insights into how trans genes are being exploited to discover new knowledge in animals and plants. The papers were presented by leading investigators in the biological sciences, and the book reflects an experiment in interdisciplinarity which was declared a successful venture by the large crowd of participants and delegates. The transgenic area is one of high scientific interest and sporadic, yet intense biotechnological euphoria. This is dramatically illustrated among the following papers which show how genetic maps of animals and plants produce new knowledge of disease incidence in humans, and how the design of transgenes can result in biodegradable plastic in higher plants, human pharmaceutical proteins in livestock, or bacterial proteins in cotton crops to protect against insect damage.