STUDIES ON HAEMOLYSIS. 31 



tedious by the fact that in some cases in which the production of 

 an isolysin is attempted after the method already outlined, no iso- 

 lysin is formed. We have records of a number of goats in which 

 the injection of goat blood produced apparently no effect whatever; 

 among these is one which was injected with its own blood. 



The difference in the isolysins in their dependence on the injected 

 blood and on the individuality of the treated animal, the fact that 

 there is formed always an isolysin, not an autolysin, the special con- 

 ditions governing the formation of the anti-isolysins, the failure of 

 the isolysin reaction in certain cases, all these make the problems 

 connected with the above facts appear very complicated, and make 

 it necessary now to analyze these more closely. 



Every red blood-cell possesses a large number of side-chains with 

 haptophore groups, each of which is able to combine in the animal 

 body with fitting receptors/ Let us, in our own case, designate such 

 a group of the injected goat erythrocytes as group a, and a corre- 

 sponding receptor as receptor a. There will then be presented two 

 possibilities. First is the possibility that the a. receptor is entirely 

 absent in the organism of the goat into which the blood is injected. 

 If this be the case, there is lacking the essential condition for the 

 formation of any reactive product, and the result of the injection 

 will be entirely negative. 



If, however, the second possibility obtains, and a receptors are 

 present in the body of the animal injected, there are again tw T o ways 

 in which the reaction may proceed: (1) the a receptors exclusively 

 may be present; (2) besides these, the organism may contain the 

 same group a which is present in the injected blood-cells. 



We shall study these tw r o cases separately and begin with the 

 simpler, in which only a receptors are present. In this case the 

 conditions for the formation of a hsemolysin are given and the bind- 

 ing, hyper-regeneration, and final thrusting-off of the a receptors 

 will follow. This newly formed immune body, in conjunction with 

 ;he complement always normally present, will dissolve all those goat 

 olood-cells, and only those, which possess the group a. But as 

 this group a, according to our assumption, is completely absent in 

 the organism of the animal itself, the immune body fails here to 

 find any point of attack. The immune body therefore wall accu- 

 mulate in the blood without hindrance and without causing the 

 slightest damage to the organism. This case is the one w r hich applies 

 to the examples of isolysin formation described by us, for it is the 



