220 MANUAL OF PHYSIOLOGY. 



Mice, 



Guinea pig, ................. rV-zV 



Rabbit, .... ................. 1*5- A- 



Dog, ............. ..... ... . i-Ws- 



Cat, ..................... JT- 



Birds, ..................... T V- T V 



Frog, . .................... T Wo- 



Fish, 



Only approximate estimates of the distribution of blood in the 

 body during life can be made, since there can be no accurate 

 method of investigation, and the amount varies enormously, 

 according as the organ or part is in a state of rest or activity. 

 It is supposed that a quarter of the entire amount is habitually 

 flowing through the heart and great vessels, a quarter in the 

 skeletal muscles, another quarter in the liver, and in all the other 

 parts only a fourth. 



PHYSICAL CONSTRUCTION OF THE BLOOD. 

 As already stated, the blood is not a red fluid. It is seen with 

 the microscope to be made up of a clear fluid called plasma or 



FIG. 95. 



Human Blood afier death of the elements. The red corpuscles are seen in different 

 positions showing their shape, some also are seen in rolls. Only one white cell (w) 

 is seen, misshapen and entangled in fibrin threads. 



liquor sanguinis, which contains an immense number of little 

 disk-shaped bodies called red corpuscles, and a few colorless pro- 

 toplasmic cells, which are called white corpuscles; so that the 

 living blood may be physically tabulated, giving approximately 

 an estimation of the relative amounts, thus : 



Plasma or Liquor Sanguinis f . 



Blood < Solid or Corpuscle { Red disks 1 -f. 



1 Pale cells j J 



