258 THE ANIMAL. XII. 



The following table embodies some of their results : 



Percentage composition of the whole bodies of animals. 



It will be seen from the above figures that the nitrogenous 

 matter is the most constant in quantity and that the water 

 and fat vary inversely with each other. The amount of ash is 

 chiefly dependent upon the proportion of bones to the rest of 

 the body. 



Among the most important parts of the animal body the 

 following may be mentioned : 



(1) The blood. 



(2) The bones. 



(3) The muscles. 



(4) The connective tissues. 



Blood consists of a transparent colourless liquid, the blood 

 plasma, in which an immense number of solid particles, the 

 red and colourless corpuscles, are suspended. When taken from 

 the body, unless special precautions are observed, blood coagu- 

 lates or clots with a rapidity which varies with different 

 animals and also with the temperature ; if cooled quickly 

 coagulation is retarded ; the blood of the horse coagulates 

 more slowly than that of other animals. 



In clotting, a separation into a clear yellow liquid blood 

 scrum and a red solid blood clot occurs. This separation is 

 brought about by the coagulation of a proteid fibrinogen 



