454 H^EMOLYSINS AND ALLIED BODIES 



ment in Ehrlich's sense) to form a new compound which does not 

 act as a hsemolytic agent. The structure of this compound would 

 therefore be haemolysin + anti-hsemolysin. 



Like anti-bodies in general, anti-complements can withstand 

 a temperature of 55-60 C. For their detection, therefore, the 

 serum in which they exist is heated to the above temperature so as 

 to inactivate any complements which it contains, and which might 

 react with any suitable amboceptors in the blood with which it 

 was mixed, and thereby mask the action of the anti -complement. 

 For example, suppose we wish to study the anti-complements pro- 

 duced in rabbit's blood by the injection into the rabbit of guinea- 

 pig's serum rendered hsemolytic towards rabbit's erythrocytes. 

 If the anti-complement containing serum were directly mixed with 

 a hsemolytic serum (produced by injecting rabbit's erythrocytes 

 into a guinea-pig) the complements which that serum contains 

 would unite with some of the amboceptors present in the immunised 

 (guinea-pig's) serum, and would, consequently, mask the full action 

 of the anti-complement i.e. a certain amount of haemolysis of the 

 rabbit's erythrocytes would ensue. Whereas, if the anti-comple- 

 ment containing serum be heated no haemolysis will follow. 



Anti-complements are specific bodies; the anti-complements 

 developed in rabbit's blood by the injection of guinea-pig's serum 

 can only inhibit the action of the complements of guinea-pig's 

 serum, unless, as a coincidence, it should happen that some other 

 blood possesses complements with haptophoric groups which fit 

 those anti-complements. Now we have seen that there are various 

 complements present in serum. On injecting the serum of one 

 animal into another, certain of these complements, but not all of 

 them, will meet with receptors on to which they can anchor, and 

 the liberated receptors, i.e. anti-complements, will inhibit the action 

 only of some of the complements of the blood used for injection. 



With regard to the exact nature of the receptors which form 

 the anti-complements, Ehrlich and Morgenroth consider them as 

 similar to amboceptors (i.e. of the third order), with the differ- 

 ence that the complemento-philic group has acquired greatly 

 increased combining powers. 



When anti-complements are present in the blood along with 

 complements, whose action they can prevent, they are called 

 anti-auto-complements. They never appear spontaneously in the 

 blood, but, as Ehrlich and Morgenroth have shown, they can be 

 experimentally produced. Thus, as we have seen above, normal 



