BACTERIOLOGY IN A NUTSHELL. 



Wright's 

 Answer Final. 



Derivation 

 of Opsonin. 



Attempts to answer this have given rise to many 

 theories and much theorizing. Over in one of 

 the great English* hospitals there is a man, 

 Sir A. E. Wright, who has asked this ques- 

 tion and has answered it with such finality that 

 the scientific world has almost accepted it as 

 proved. He has found that there are in the 

 blood serum or plasma certain substances which 

 act upon bacteria in such a way as to prepare 

 them to be ingested and destroyed by the 

 leucocytes. Without this substance or these 

 substances the leucocytes are powerless. To 

 this power, substance or property of the blood 

 has been applied the term Opsonic derived 

 from the Greek word Opsono, meaning "I pre- 

 pare food for" or "I prepare for dinner." For 

 our purposes it matters little what the proper- 

 ties and characteristics of opsonins are. Ap- 

 parently there is a different opsonin in the blood 

 for each form of bacteria. It is a fact readily 

 observed that an individual often succumbs to 

 one infection more readily than to another; 

 likewise the same individual at one time seems 

 immune to a certain bacterial disease, at an- 

 other he quickly falls a victim to the same 

 affection. According to our opsonic theory 

 we would explain these facts by the varying 

 degree of opsonic power of the blood. Instead 



* St. Mar/s Hospital, Pad'dingtoti District, Londicm, 

 England, where W!right established a department of 

 scientific researcb in IfliOB. 



60 



