112 HUMAN PHYSIOLOGY. 



Paraglobulin or fibrinoplastin is a soft, amorphous substance precipitated 

 by sodium chloride in excess, or by passing a stream of carbonic acid through 

 dilute serum. 



Fibrinogen also can be obtained by strongly diluting the serum and passing 

 carbonic acid through it for a long time, when it is precipitated as a viscous 

 deposit. 



Fatty matter exists in the blood to the extent of about o . 25 per cent. Just 

 after a meal rich in fat, this amount may be considerably increased. Within 

 a few hours it disappears, though its ultimate fate is unknown. 



Sugar is represented by dextrose. The amount present varies from o.i 

 to 0.3 per cent. It is derived directly from the glycogen of the liver. Should 

 the normal percentage be increased, the sugar is eliminated by the kidneys. 



The inorganic constituents are chiefly sodium and potassium chlorids, 

 sulphates and phosphates together with calcium and magnesium phosphates. 

 The sodium chlorid is the most abundant, amounting to about 5.5 parts per 

 thousand. The alkaline salts impart the alkaline reaction and promote the 

 absorption from the tissues of the carbon dioxid. 



Excrementitious matters are represented by carbonic acid, urea, creatin, 

 creatinin, urates, oxalates, etc. ; they are absorbed from the tissues by the 

 blood and conveyed to the excretory organs, lungs, kidneys, etc. 



Gases. Oxygen, nitrogen, and carbonic acid exist in varying proportions. 



BLOOD-CORPUSCLES. 



The corpuscular elements of the blood occur under two distinct forms, 

 which, from their color, are known as the red and white corpuscles. 



The red corpuscles as they float in a thin layer of the liquor sanguinis are 

 of a pale straw-color; it is only when aggregated in masses that they assume 

 the bright red color. In form they are circular and biconcave; they have an 

 average diameter of ^TT of an i ncn - 



In mammals, birds, reptiles, amphibia, and fish the corpuscles vary in 

 size and number, gradually becoming larger and less numerous as the scale 

 of animal life is descended, e. g. : 



TABLE SHOWING COMPARATIVE DIAMETER OF RED CORPUSCLES. 

 Mammals. Birds. Reptiles. Amphibia. Fish. 



