THE COMPOUND HJEMOLYSINS 243 



As we have seen before, the immune-bodies in the rabbit 

 treated with ox erythrocytes, and in the goat treated with 

 sheep erythrocytes are almost completely absorbed by 

 the red blood-corpuscles (cf. p. 150) in weak solutions. 

 The same is probably the case for the immune-body from 

 a goat treated with ox erythrocytes. The formation of 

 haemolysin is, without doubt, effected only in the red 

 blood-corpuscles themselves, for these absorb the immune- 

 body before a reaction takes place (cf. p. 220). On the 

 other hand, they dissolve very little of the alexin, but this 

 is combined with the immune-body, so that new alexin 

 enters and forms the poisonous haemolysin. The circum- 

 stance that the alexin always enters to the power i would 

 then indicate that the alexin has the same molecular weight 

 in the blood-corpuscle and in the surrounding fluid, so 

 that a constant fraction, probably very little, is always con- 

 tained within the blood corpuscles. In the equation of 

 reaction this fraction should probably be introduced, but 

 if instead of that we, as in the formulae above, write the 

 whole quantity of alexin, that has no other effect than that 

 the constant of equilibrium changes in a certain pro- 

 portion. The haemolysin formed probably remains for 

 the greatest part absorbed in the red blood-corpuscles. 



As for lecithin, it probably enters very easily into the 

 red blood-corpuscles, and therefore plays the r61e of an 

 immune-body. 



The action of the compound haemolysins is therefore, like 

 that of the simple haemolysins, based upon their presence 

 in the red blood-corpuscles, which are thereby so changed 

 that the membrane becomes permeable to haemoglobin. 



As we have seen before, the immune-body at higher 



