OXYGEN AND CARBON DIOXIDE TRANSPORT BY THE BLOOD OF THE URODELE, AMPHIUMA TRIDACTYLA

¹ From the Department of Physiology, and the Department of Research Medicine, School of Medicine, University of Pennsylvania

1. The corpuscular volume of Amphiuma blood varies considerably, from 12 to 35 per cent.

2. The oxygen capacity varies from 3 to 10 volumes per cent.

3. It is shown that the oxygen dissociation curve is like the typical mammalian curve with certain features in common with those of the turtle and carp.

4. The presence of physiological amounts of carbon dioxide affects the oxygen dissociation curve in the usual way.

5. The comparative values of n and K₀ of the Hill equation are given for the blood of Amphiuma, carp, turtle and man, and the equation of Hill for these bloods is shown to hold within the limits specified.

6. The mechanism for the transport of carbon dioxide in the Amphiuma blood is much like that in the turtle and the flatness of the carbon dioxide absorption curve is explained as a function of the limited amount of hemoglobin.

7. The difference in carbon dioxide carried by oxygenated and reduced blood is quite small and probably has little physiological significance, though the increase in carbon dioxide content per unit of oxygen capacity is in the same direction as that for man.