RED BLOOD CORPUSCLES 37 



The most abundant salt of the plasma is sodium chloride. 

 It forms from 60 to 90 per cent, of the total mineral matter 

 of plasma. Potassium chloride is present in much smaller 

 amount. Other salts are the carbonates, sulphates and phos- 

 phates. 



Corpuscles. 



Suspended in the plasma of the blood we have a cellular 

 formed element moving and functionating. This element is 

 the corpuscular element and is composed of (a) the red 

 blood corpuscles, (b) the white blood corpuscles, (c) the 

 blood platelets. 



(a) Red Blood Corpuscles or Erythrocytes. 



General Description. The red blood corpuscles are circu- 

 lar, bi-concave discs with rounded edges. They are from 7 

 to 8 micra in diameter and 2 micra in thickness, so can only 

 be seen with the aid of the microscope. When looked at 

 singly they appear to have a yellowish-green color, collec- 

 tively they are red. 



Number. In males there are about 5,000,000 red cells per 

 cubic millimeter ; in females about 4,500,000. The propor- 

 tion of reds to whites is one white to every 500 red. 



Origin and Destruction. The red corpuscles are continu- 

 ally being destroyed in the body. It appears that this de- 

 struction occurs principally in the liver. As the red cells 

 are thus destroyed it is natural to look for a place of manu- 

 facture. In the embryo we find that this generation takes 

 place in the liver and in the spleen ; in the adult it seems that 

 the manufacture takes place only in the red marrow of the 

 bones. 



The red corpuscles are formed from colored, nucleated 

 cells called hemoblasts. 



Constituents of Red Blood Corpuscles. The red blood 

 corpuscles are made up of 65 per cent, water and 35 per 



