20 PROPERTIES OF ILEMOLYTIC SERA 



from the same animal. Furthermore, in speaking of suita- 

 bility of complement, a distinction has not been drawn 

 between combining affinity and toxic effect. As judged 

 from the minimum heemolytic dose for ox's corpuscles, 

 guinea-pig's complement acts better with the immune-body 

 from the rabbit than does rabbit's complement itself. 

 This is chiefly due to the fact that the guinea-pig's serum 

 has a greater number of active molecules than the rabbit's 

 has (p. 45), but it really also combines more efficiently as 

 judged by absorption experiments. Too few examples 

 have been intimately studied to permit a definite state- 

 ment to be made on this subject. 



Another argument in favour of the amboceptor view is 

 drawn from the facts established with regard to cobra 

 venom by Kyes \ The chief points are, that the haemolytic 

 toxin of this venom in many cases cannot by itself pro- 

 duce lysis of corpuscles, but requires the addition of a sub- 

 stance like lecithin, the latter thus apparently acting 

 like complement. Furthermore, it has been shown that the 

 lecithin unites directly with the toxin, forming the so-called 

 cobra lecithid. In this case, accordingly, the venom mole- 

 cules act like amboceptors. These facts are highly sugges- 

 tive in themselves, but it would be unjustifiable without 

 direct evidence to generalize from them with regard to 

 serum complements, which are of a very different nature 

 from substances of definitely known chemical constitution 

 like lecithin. The fact that an anti-immune-body, which 

 has a comparatively specific action on the immune-bodies 

 of the species of animal whose serum has been used in its 

 development, produces its effect by preventing the union 

 of complement, would appear to indicate that the anti- 

 immune-body acted by filling up the complementophile 

 groups of the immune-bodies (amboceptors). There are, 

 however, difficulties in accepting this comparatively simple 

 1 Kyes, Berlin. Klin, Woch., 1902, nos. 38, 39 ; 1903, nos. 42, 43. 



