Physical properties of surfactant from the lungs of the tortoise Testudo hermanni

1.1. Interfacial films were formed in vitro from surfactant extracted from the lungs of tortoises (Testudo hermanni).2.2. The surface pressure, surface potential and surface viscosity of these films were similar in magnitude to the values previously found in mammals.3.3. The surface pressure, surface potential and surface viscosity of the films were dependent on temperature throughout the range 19–34°C.