FUNCTIONS OF THE BLOOD 287 



this mechanism the red corpuscles of animals of a different species 

 are as much foreign bodies to be attacked and destroyed as are 

 the most malignant bacteria. The introduction of foreign blood, 

 even if not attended by coagulation, is therefore more apt than 

 not to be fatal, through the destruction of each kind of corpuscles 

 by the liquid portion of the other sort of blood. Fortunately the 

 operation of transfusing blood is neither excessively painful nor 

 accompanied by untoward after effects to the donor, and persons 

 can always be found who are willing to undergo the discomfort 

 involved for the sake of restoring a fellow-being to health. 



