322 



Comparative Animal Physiology 



oxygen tensions but that the effect of CO disappeared in low oxygen (Fig. 77). 

 It was calculated'-'" that of the total oxygen used by the worm 23 per cent is 

 carried by hemoglobin at 152 mm.O.,' 35 per cent at 76vmm. O., 40 per cent 

 at 35 mm. Oo, 22 per cent at 19 mm. Oo and per cent at 8 mm. Oo. Dissocia- 

 tion curves for earthworm hemoglobin are not available. 



In Nereis diversicolor inactivation of hemoglobin by CO reduces the oxygen 

 consumption bv approximately 50 per cent at high oxygen tensions (6-7 ml. 

 Oo/l.), and blocks all O2 consumption at 3.3 ml. O^A^- Nereis diversicolor, 



Fig. 77 



Fig. 78 



WITHOUT CO 



40 80 120 160 



PARTIAL PRESSURE OF OXYGEN-MM MERCURY 



(I) Op CONSUMPTION- NORMAL ANIMALS 



(2)02 CONSUMPTION -CO ANIMALS 



(3) RESPIRATION DUE TO HEMOGLOBIN 



> 



O2 IN CC/L 



OXYGEN CONCENTRATION (c.c./l) 



CC/L 



Fig. 79 



Fig. 80 



Fig. 77. Oxygen consumption by huvnihricus as a function of oxygen tension with 

 and without carbon monoxide. From Johnson.™ 



Fig. 78. Oxygen consumption by Chironomus as a function of oxygen tension 

 in the presence and absence of CO. From Ewer.^* 



Fig. 79. Oxygen consumption by Tubifex as a function of o.xygen tension in presence 

 and absence of CO. Curve 3 is the difference between curves 1 and 2. From Dausend."' 



Fig. 80. Oxygen consumption by Sabella pavonia as a function of oxygen tension with 

 the chlorocruorin: 0> unpoisoned and •, poisoned by CO. From Ewer and Fox.*' 



