334 STUDIES IN IMMUNITY. 



having each an affinity lor one certain "complement." By natu- 

 ral law, only the smallest number of such bodies in scrum would 

 have " complementophilic " arms suitable to join with the proper 

 "complement" of the corpuscles to be destroyed. In the given 

 case a hemolytic dose of the guinea-pig > rabbit immune serum with 

 guinea-pig "complement" may be represented by the formula 1 A 

 -I- tV B, "A" being partial immune bodies joining only with the 

 guinea-pig complement, "B" being partial immune bodies joining 

 only with the rabbit complement. In order to obtain hemolysis 

 with rabbit complement it is necessary, logically, to have ten such 

 doses (i.e., 10 A + 1 B) in order to have one whole dose of "B." 

 Ehrlich and Morgenroth* have sought further to establish this 

 hypothesis of the multiplicity of immune bodies in a given immune 

 serum by means of certain experiments with anti-immune bodies 

 — a subject which we need not here consider. 



After my first results on the subject I found that this interesting 

 question had already been considered in part by Muir and Brown- 

 ing,! wno have come to practically the same conclusions as myself, 

 although they were unable wholly to refute the hypothesis of the 

 multiplicity of immune bodies on account of certain technical diffi- 

 culties; these difficulties I have been able to obviate by a specially 

 devised method. 



Although nowhere expressly stated by Bordet or by Ehrlich and 

 Morgenroth, I have found, in common with Muir and Browning, 

 that, when we reactivate sensitized rabbit corpuscles (heated guinea- 

 pig > rabbit immune serum) with rabbit alexin, not only is the 

 requisite dose of immune body large, but also the dose of rabbit 

 alexin relatively high. The relative amounts of the immune serum 

 necessary in the presence of sufficient alexin of either animal, and 

 the relative amounts of each alexin when sufficient immune body 

 is present are so well shown in the tables of Muir and Browning 

 that I omit similar examples. As regards the relatively high dose 

 of rabbit alexin against its own corpuscles the following (Table I) 

 shows that it takes nearly three times as much alexin to destroy 

 numerically a smaller number of its own sensitized corpuscles than 

 of sensitized ox corpuscles. 



* Ehrlich and Morgenroth, See Collected Studies on Immunity, Ehrlich- 

 Bolduan, John Wiley & Sons, p. 101. 



t Muir and Browning, Proceed. Royal. Soc, Vol. LXXIV, 1904, p. 298. 



