PHYSIOLOGICAL OBSERVATIONS UPON A LARVAL EUSTRONGYLIDES. XI. INFLUENCE OF OXYGEN TENSION ON THE AEROBIC AND POST-ANAEROBIC OXYGEN CONSUMPTION

1. The oxygen consumption of larval Eustrongylides ignotus shows a greater dependency on the oxygen tension at high than at low temperature. 2. The post-anaerobic oxygen consumption is more dependent on the tension than the respiration of larvae that were exposed previously to well oxygenated surroundings, if experiments performed at equal temperatures are compared. This difference disappears almost completely, however, if experiments are compared in which the intensity of the oxygen consumption was equal in both sets at a tension of 760 mm. Hg. 3. The implication of these data is discussed on the controversy between Harnisch and von Buddenbrock as to whether it is justified to distinguish between "primary" and "secondary aerobiosis." 4. The dependency of the oxygen consumption on the tension is a true one and is not only simulated by oxygen going into physical solution in the body fluids at higher tensions. 5. The larvae of Eustrongylides, in contrast to Ascaris, are not killed by a 6-hour exposure to pure oxygen.