64 MODERN BIOLOGIC THERAPEUSIS 



taken up in too great quantities by those vital 

 tissue-cells which have an affinity for it, in or- 

 der to effect a cure of the disease. Antibac- 

 terial sera, represented by Antipneumococcus 

 Serum, act directly upon the invading bacteria 

 and render them inert or aid in their destruc- 

 tion, thereby arresting the disease. 



Types of Antibodies The antibodies in an- 

 titoxic sera are chiefly antitoxins, substances 

 which neutralize the bacterial poisons or tox- 

 ins; while the antibodies in antibacterial sera 

 consist of bacteriolysins, agglutinins, precipi- 

 tins, opsonins, and other substances, all of 

 which act directly upon the bacteria and aid in 

 destroying them and their intracellular prod- 

 ucts. In contrast to immune sera, normal se- 

 rum does not contain any specially induced 

 antibodies, but is used on account of its hemo- 

 static properties. 



