78 PHYSIOLOGY 



If there is an excess in combination, the passage will be 

 very rapid out of the hemoglobin. 



Oxygen Can Not Establish an Equilibrium. — Theo- 

 retically an equilibrium tends to establish itself (1) 

 between the oxygen in solution and that in combination 

 with hemoglobin, (2) between the oxygen in solution and 

 that in the air in the lungs, and (3) between the oxy- 

 gen in solution and that in the cells ; but practically no 

 equilibrium is possible in these cases because oxygen is 

 continually passing out of solution into the cells where it 

 is used and into the hemoglobin where it is stored. The 

 pressure of oxygen is thus kept low in the solution, in 

 response to which oxygen passes into the solution from 

 the outside air. 



Origin and Fate of the Red Corpuscles. — The red 

 corpuscle^ £r^ ^formed in the red marrow of the bones 

 and when very young they r have a nucleus. As they 

 mature they lose it, and in consequence they disintegrate 

 very easily, usually in the spleen or in the liver. In 

 high altitudes the rare air contains very little oxygen, 

 •but in compensation for its diminished flow into the 

 blood the number of red corpuscles increases rapidly. 

 As the amount of hemoglobin is increased, oxygen is 

 removed from the solution faster than usual. It thus 

 becomes more difficult to establish an equilibrium and 

 the tissues have a better chance of getting from the 

 rare atmosphere enough oxygen to maintain life. 



The White Corpuscles. — The white corpuscles are 

 translucent, irregular in shape, and they have more than 

 one nucleus. They resemble the ameba and like it they 

 can move from place to place (Fig. 51). They work 



