566 IDENTITY OF OPSONINS WITH NORMAL AGGLUTININS, 



clearly evident that any enumeration of the englobed bacteria 

 would be misleading and of no value whatsoever. It was also- 

 found that Bac. diphtherice did not markedly differ from £ac. 

 typhi, Bac. coli, Bac. dysenterice (Shiga), Micr. melitensis, or Vib. 

 cholei'ce* The opsonic power was reduced but never destroyed by 

 heat. 



Although the experiment was mainly intended to demonstrate 

 the recovery of the opsonic power after heating, this could not be 

 done for the following reason. When dead suspensions of Bac. 

 coli or Bac. tyiohi are kept in contact for 24 hours with serum 

 that has been heated at 60° the greater part of the staining 

 power is lost. A considerable portion disappears by contact 

 with heated (62-5°) serum and a small part with dilute serum 

 that has been heated at 65° for 15 minutes. This factor contri- 

 buted largely to prevent a reliable enumeration.! The obser- 

 vation raises the question, are the alexines of the serum destroyed 

 by heat as easily as is generally supposed ? 



An experiment with Bac. typhi and Bac. coli showed that they 

 were opsonised extensively by diluted serum heated at 60°, 62-5° 

 and 65°. Phagocytosis in all cases was pronounced; the majority 

 of the polynuclear leucocytes were gorged with bacteria in all 

 stages of disintegration. 



The instances of similarity between the opsonins and agglu- 

 tinins, that I have brought forward, point strongly to the pro- 

 bable identity of the two. But there are other indications of 

 similar behaviour. There is a rise, fall, and presumably higher 

 base level of the agglutinins during the course of uncomplicated 

 typhoid fever. This has been shown by Jorgen.sen| and by 

 Iverson.§ It appears to be akin to the positive phase and 



* These bacteria were obtained from Dr. Tidswell, of the Board of Health, 

 Sydney. 



t Mici\ melitens^is was the only micro-organism that showed an increased 

 phagocytic index in the case of the long contact with heated serum, doubtless 

 because it is more resistant to the action of the bacteriolytic bodies. 

 + Cent. f. Bakt. (Orig.) xxxviii. (1905), 475, 566. 

 § Zeitsch. f. Hygiene, xlix. 1. 



