420 



On the Recognition of the Individual hy Hcemolytic Methods. 



found to have lost its haemolytic action, not only for the corpuscles of the cow, 

 but also for those of its calf. 



It is worth noting, however, that the serum exhausted with the corpuscles 

 of the calf was specific for the calf. 



Taking advantage of the fact that the isolysins for the ox act very 

 powerfully on the corpuscles of the goat, we have made a series of experiments 

 to test the utility of the method in investigating the corpuscles of closely 

 related individuals. The method works well and is giving very interesting 

 results. 



These results show that the red blood cells of different individuals of the 

 same species are not only not identical, but that they are characterised by a 

 definite individuality and can be distinguished from the red blood cells of any 

 other individual. 



How far this is part of a general law affecting the other cells of the body is 

 at present under investigation. 



We are of the opinion that the method of investigation by means of 

 exhausted polyvalent immune sera will prove most valuable in biological 

 research not only as a means of identifying the cells of the individual, but in 

 the investigation of the laws of heredity and many other important problems. 



Conclusions. 



1. The immunisation of the ox with the red blood corpuscles of other oxen 

 gives rise to the formation of a hsemolytie amboceptor in the blood of the 

 immunised animals. 



2. The amboceptor so formed is an isolysin but not an autolysin. 



3. The race of tlie animal appears to have very little influence on the 

 resulting luemolysins. 



4. The serum of an animal so treated acts very differently on the red blood 

 corpuscles of different individual oxen. 



6. The sera of different individuals similarly immunised differ from one 

 another in their action on the corpuscles of different individuals. 



G. If the serum of a single immunised animal be " exhausted " with excess 

 of the corpuscles of one other individual, the serum loses its power of 

 htemolysing the corpuscles of this individual, while retaining the power of 

 h;emolysing the corpuscles of many, but not all, otlier individuals. 



7. If, however, a polyvalent serum be made by inixing the sera of a large 

 number of immunised animals, and this serum is exhausted with the 

 corjjuscles of any one individual, the serum entirely loses its power of 

 hfcraolysing the corpuscles of this individual, but remains strongly htcmolytio 



