STRICTURE OF OPSONINS. 61' 



generally regarded as belonging to the anti- bodies of 

 the second order of Ehrlich. They apparently possess two groups, 

 the opsonophore and the haptophore. Of these the opsonophore 

 L-nmp is destroyed by heat, age, acids, etc. It is thus seen that 

 immune opsonins resemble the agglutinins and precipitins in 

 structure and by some investigators bave been thought to be 

 identical with agglutinins. 



Normal opsonins, though not acknowledged by Wright to 

 be different from immune opsonins, have characteristics by which 

 they differ from immune opsonins. Normal opsonins resemble 

 complement in that they are absorbed or fixed by sensitized and 

 non-sensitized bacteria, blood corpuscles, specific precipitates and 

 indifferent bodies, and exhibit thermolability and susceptibility 

 to deterioration by age. Noguchi has found that normal opsonins 

 resemble complement in that they are highly labile bodies, loose 

 their action on standing several days, are preserved for a long 

 time when present in blood in a dry state, and in this condition 

 can be heated to 135 C. without destruction of their functions. 

 Recently Muir and Martin, Levaditi and Inman, and Hiihne and 

 Neufeld have ascribed the action of normal opsonins to comple- 

 ment. Cowie and Chapin have found that normal guinea pig 

 serum restores the opsonic power to normal serum which has been 

 heated to 55 C. They believe from their experiments that opso- 

 nins (normal?) exert their action because of an amboceptor-com- 

 plement group. Hektoen has recently published results of experi- 

 ments from which he concludes that the activating element is free 

 from the opsonin and therefore he believes that opsonins belong to 

 the third order of anti-bodies of Ehrlich. 



It now seems quite definitely established that the action of 

 normal and immune opsonins is due to entirely different factors 

 in immunity, and that immune opsonins are distinct anti-bodies 

 probably belonging to those of the second order of Ehrlich. 



RELATIONS OF OPSONINS TO LEUCOCYTOSIS. 



No consistent relation has been found to exist between changes 

 in opsonic index and general or localized increase in the number 

 of leucocytes. Simonds and Baldauf have recently found that fol- 

 lowing an injection of heated bacteria there is a decrease in leuco- 

 cytes after which there is a marked increase in leucocytes with an 



