THE INFLUENCE OF OXYGEN TENSION UPON THE RESPIRATION OF UNICELLULAR ORGANISMS

¹ From the Department of Physiology, School of Medicine, University of Pennsylvania, and the Marine Biological Laboratory, Woods Hole, Mass.

By standard methods of gas analysis the respiratory exchanges of Paramecium and of fertilized Arbacia eggs have been studied. The respiratory rate in both materials is found to be practically constant over a wide range of oxygen tensions, thus confirming older work done by other methods.

In the fertilized Arbacia egg the oxygen consumption is practically constant between 228 and 20 mm. Hg partial pressure of oxygen. Between 80 and 20 mm. Hg there appears to be a slight diminution in oxygen intake, but at 20 mm. Hg the consumption is still about 90 per cent. of that at atmospheric pressure. Below 20 mm. Hg the consumption is sharply reduced.

The cleavage of Arbacia eggs proceeds at a normal rate down to very low oxygen tensions. No retardation in development has been observed above 11 mm. Hg. Below this value the rate becomes slower and cleavage ceases entirely below 4 mm. Hg.

This article has been cited by other articles:

				W. Kempner THE ROLE OF OXYGEN TENSION IN BIOLOGICAL OXIDATIONS Cold Spring Harb Symp Quant Biol, January 1, 1939; 7(0): 269 - 289. [Abstract] [PDF]

				Theo. L. Jahn PROBLEMS OF POPULATION GROWTH IN THE PROTOZOA Cold Spring Harb Symp Quant Biol, January 1, 1934; 2(0): 167 - 180. [Abstract] [PDF]