Abstract

After World War II, various toads replaced mice and rabbits as pregnancy-test animals in diagnostic laboratories around the world. This talk examines the divergent strategies adopted by competing laboratories to acquire and maintain stock of exotic and domestic toads for human pregnancy diagnosis in postwar Britain. Commercial dealers and the Department of Inland Fisheries in South Africa harvested the locally abundant species, Xenopus laevis, from the wild and attempted to breed the animal in captivity. However, as only a handful of large and specialised ‘pregnancy diagnosis centres’ in Britain could afford the elaborate and expensive equipment required to sustain a healthy colony of Xenopus, many small hospital laboratories preferred the ordinary British toad, Bufo bufo, which they could obtain and discard indiscriminately. Ironically, the imported Xenopus proved less resistant to laboratory life in Britain than did the domestic Bufo, which often starved to death or died of ‘unknown causes’ in captivity.