DIFFERENCES IN COMPOSITION OF BLOOD. 471 



V 



An important distinction between arterial and venous 

 blood is one to which we have already incidentally alluded, 

 viz., that the former has a uniform composition in all parts of 

 the arterial system, while the composition of the latter varies 

 very much in the blood coming from different organs. Arte- 

 rial blood is capable of carrying on the processes of nutrition ; 

 while venous blood is not, and cannot even circulate freely 

 in the systemic capillaries. 



