Sensitivity of <i>Paramecium Caudatum</i> to High Oxygen Tensions and Its Modification by Cobalt and Manganese Ions

Abstract

Paramecia were put in a hanging drop in a special chamber in which they could be observed under the microscope while they were exposed to different pressures of oxygen. Characteristic morphological changes were recorded photographically and were found to be very similar to changes induced by radiation. Survival times decreased from 8.05 hours at 2 atm. to 0.87 hours at 20 atm. of pO 2 . Treatment with cobalt (II) chloride and manganese (II) chloride (m/200,000) increased the survival times at 9 atm. and decreased them at 2 atm. pO 2 .