TOXIC ACTION OF COMPLEMENTS 83 



As lysis does not occur in the first stage, the contents 

 of each tube are centrifugalized, and the fluid is added to 

 the guinea-pig's corpuscles. The following results were 

 obtained : 



Experiment LXXIIL 



1 D of IB took up 0-04 c.c. ox's C. 

 4 0-05 



^ J> >5 



Dose of ox's complement for guinea-pig's corpuscles = 

 0-03 c.c. 



Experiment LXXIV. 



1 D of IB took up 0-014 c.c. ox's C. 

 4 0-02 



)> JJ 5> 



Dose of ox's complement for guinea-pig's corpuscles = 

 0-02 c.c. 



From these it is evident (1) that a considerable amount 

 of ox's complement is taken up by one dose of immune- 

 body (i.e. by 1 M.H.D. as tested with rabbit's or guinea- 

 pig's complement), but this amount of complement, which 

 may be more than sufficient to produce complete lysis of 

 rabbit's or guinea-pig's corpuscles, produces almost no lysis 

 of the ox's corpuscles; and (2) that the total amount of 

 complement which can be taken up is almost reached with 

 one dose of immune-body, additional doses of immune- 

 body scarcely increasing the amount. There is, of course, 

 in this case, no possibility of the phenomenon being due 

 to dissociation of complement after combination, as the 

 ox's corpuscles are removed by centrifugalization before 

 the guinea-pig's corpuscles are added, and, therefore, any 

 complement obtainable must have been free in the fluid. 

 Accordingly, we have here, again, an example of the relative 

 non-sensitiveness of an animal's corpuscles to the action 

 of its own complement when it is brought into union with 



G2 



