BACTERIOLYSIS AND ALLIED PHENOMENA 177 



amounts too large or too small being without effect. This was 

 also corroborated by Kyes and Sachs, who showed that in 

 presence of an excess of venom (amboceptor) the addition of a 

 haemolyzing amount of complement might be without effect. 

 Now Kyes had already shown that venom does unite directly with 

 one of the substances (lecithin) which can complement it, and 

 this appeared strong evidence in favour of Neisser and Wechs- 

 berg's explanation. But Noguchi afterwards showed that the 

 protective action of large doses of venom protects the red cor- 

 puscles against the action of haemolytic agents other than comple- 

 ments. Corpuscles so treated are not dissolved by distilled water 

 or by tetanolysin. It appears, therefore, that strong solutions of 

 venom have a curious hardening effect on red corpuscles, render- 

 ing them resistant to haemolytic agents of all sorts. This effect 

 is apparently entirely different from the protection of a bacterium 

 by excessive doses of amboceptor, and should not be used as 

 evidence to support Neisser and Wechsberg's explanation. 



Morgenroth has attempted to explain the absence of the devia- 

 tion of the complements in haemolysis by alleging that in this case 

 the amboceptors and complements do not unite until the former 

 have united with the red corpuscles ; this, of course, is the point 

 at issue. He finds that by adding anti-amboceptor (for the cyto- 

 phile group) to a mixture of amboceptor and complement the 

 phenomenon of deviation can be reproduced. But his experiment 

 can probably be explained by means of Gay's observations, to be 

 explained subsequently, and in any ease his anti-amboceptor would 

 only act as a free receptor of a red corpuscle, and the amboceptor 

 attached to it would be in the same condition as one anchored to 

 a corpuscle, which we know can absorb complement. In any case, 

 his experiment proves little or npthing. 



Some experiments by Meakins afford the best evidence in 

 favour of the alteration in combining affinity undergone by ambo- 

 ceptor after union with complement, and call for short reference, 

 though their interpretation is somewhat uncertain. Meakins 

 experimented with corpuscles which had been very thoroughly 

 washed so as to remove all trace of serum. The importance of 

 this precaution will appear subsequently. He found that when 

 he added a large dose of heated immune serum and a small dose 

 of normal serum (complement) to corpuscles thus washed, and 

 allowed them to act, no haemolysis occurred. The corpuscles, 

 however, were sensitized ; for when they were centrifuged down, 



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