THE BLOOD 57 



clot formed closes the opening of the vessel. In bleeders 

 the blood does not coagulate, hence fatal bleeding is apt to 

 occur. 



2. Ether extracts: Fats, cholesterin, the ester of choles- 

 terin and fatty acid, lecithin (about 5$). 



3. Carbohydrates in the form of grape-sugar (o. I O.2$). 

 In the body the carbohydrates are carried in the form of 

 grape-sugar by the blood from one place to another. 



4. End-products of metabolism (urea, uric acid, Jcreatin, 

 xanthin, lactic acid and others) in small quantities. 



5. Salts (0.8$), chiefly NaCl (0.6$) and neutral and acid 

 sodium carbonate; also acid calcium carbonate and mag- 

 nesium sulphate in small quantities. 



Alexines and antitoxins are proteid-like substances found in the 

 plasma or serum and protect the body against infectious diseases. 

 The alexines have a bactericidal action, i.e. they destroy the 

 pathogenic micro-organisms or inhibit their action. The antitoxins 

 render the poisonous metabolic products (toxins) of the micro- 

 organisms harmless. The alexines are also responsible for the 

 globulicidal action of the blood serum (see page 54). 



