AGGLUTINATION AND DISSOLUTION. 141 



is simply an instance of intracellular digestion and entirely a 

 chance and efficient application to animal defense of a primitive 

 function which would exist even if there were no pathogenic organ- 

 isms in existence. Since this form of intracellular digestion is so 

 admirably fitted to aid in the survival of the individual it has been 

 made use of for this purpose. 



