Propagated waves induced by gradients of physiological factors within plasmodia ofPhysarum polycephalum

Plasmodia ofPhysarum polycephalum were analyzed with the aid of cinematography and the infrared reflection technique for characterization of the phase behavior of their oscillating contraction activity, with special emphasis placed on the effects of temperature gradients. In response to temperature gradients, phase gradients were documented cinematographically as well as by infrared registration. A quantitative evaluation of the cinematographically recorded phenomena was carried out with the aid of streak photography. The phase gradient is directed across the region of the temperature gradient with a delay in phase toward the colder side. The correspondingly generated waves are as short as 1 mm and are propagated toward the colder region. A comparison of these waves with the known flickering phenomena in cinematographic films reveals a common nature of both.Supported by Deutsche Forschungsgemeinschaft.