THE RESPIRATORY EXCHANGE OF DIAPAUSING PUPAE OF THE CECROPIA SILKWORM IN THE PRESENCE OF CARBON MONOXIDE

¹ The Biological Laboratories, Harvard University, Cambridge 38, Massachusetts

1. After due correction for complicating reactions, the rate of total gas uptake of normal diapausing pupae of the Cecropia silkworm in a carbon monoxide-oxygen mixture of 5 to 1 is found to be stimulated approximately 2-fold over the rate in air.

2. Ninety per cent of this extra gas uptake is due to a stimulation of the true respiration of the pupa.

3. The remaining ten per cent is due to the combustion of carbon monoxide to carbon dioxide.

4. The combustion of carbon monoxide is increased slightly when the metabolism of the pupa is enhanced following integumentary injury.

5. There is a slight fixation of carbon-14 in pupae under aerobic conditions presumably as a result of fixation of C¹⁴O₂ manufactured from C¹⁴O by the pupa.

6. There is no detectable fixation of C¹⁴O in pupae exposed to this gas under anaerobic conditions.

7. After correction for carbon monoxide-combustion, it is clear that the enhanced oxygen uptake following integumentary injury of diapausing pupae is inhibited by carbon monoxide.

8. This carbon monoxide-inhibition is directly proportional to the enhancement of oxygen uptake following injury.