The Whitney Marine Laboratory is a research institute of the University of Florida, established in 1974, and dedicated to the use of marine organisms for solving basic problems in experimental biology. The primary areas of study at the Laboratory are cell and neurobiology, but within those fields the scope is broad, including a variety of problems and approaches. The Whitney Laboratory has three strengths: it has broad technical expertise, and is particularly well instrumented for research in modern biochemistry, cell biology and physiology, an advantage maintained by support from the University and extramural agencies; a diverse fauna is available locally; and the rich animal resources of the tropics are easily accessible. Moreover, these organisms, as well as those from cold habitats, can be kept easily by virtue of a seawater supply that is unlimited, pristine and (in a new experimental aquarium facility) temperature controlled. This project will provide support for new construction and renovation to maintain and enhance the Laboratory's strengths. A new marine bio-resource facility, with work space, a collector's office and storage areas, will be built. A larger and more efficient tissue culture facility, with an adjoining room for image analysis, will be constructed. These activities will also free up space for molecular genetics, a common instrument room, and a laboratory for visiting scientists. These improvements will enhance the ability of the Whitney Laboratory to collect, maintain, and use marine animals, as well as maintaining its technological advantage in cell biology.