Abstract
1. The respiratory rate of Ascaris lumbricoides eggs embryonating at 30°C was determined at various developmental stages by means of Warburg technique at 30°C. It was 12.7μl/hr/106 eggs just after removal from the uterus and later rapidly decreased to the minimum of 4.8 μl at 45 hours after incubation. Then it increased with time to the maximum of about 20 μl at 8-14 days, which was followed by a gradual decrease to about 4.0 μl at 30-35 days. Afterwards it was kept constant but as low as 2-4 μl by the 175th day.
2. The effect of cyanide on the egg respiration was studied at 30°C and 37°C, using the eggs at 10 to 35 days. It was likely that this inhibition decreased with time in 30°C-experiments. In 37°C-experiments, it was clearly demonstrated that a high inhibition occurred in younger embryonated eggs and to a lower extent in old ones.
3. Long-term determinations (2 to 6 hours) were carried out on the eggs at 10-35 days to detect changes in their respiratory rate at 37°C. The rate of eggs at 10-20 days decreased with time over the whole period of experiments while the rate of 35-175-day-old eggs was always higher at the second reading than that at the first and was then followed by a decrease at the last and third one.
4. The above-mentioned results are discussed and interpreted from the viewpoint of physiological host-parasite relations.
