BACTERIOLYSIS AND ALLIED PHENOMENA 143 



Whilst the thermolabile substance is spoken of as : 



Alexin. Complement. 



Addiment. Cytase. 



We shall speak of the substances as amboceptor or immune 

 body and as alexin or complement respectively. Objection may be 



FIG. 24. THE CONSTITUENTS OF FRESH IMMUNE SERUM, ON EHRLICH'S 



THEORY. 



a = complement, b = amboceptor, d being its complementophile, and c its cyto- 

 phile groups. Below, a red blood-corpuscle, showing its receptors. 



This and the following figures are modified from Ehrlich, and are intended to 

 illustrate his theories of haemolysis. The black figures represent normal 

 substances (corpuscles, complement), the white ones antibodies. It need 

 hardly be said that they are absolutely diagrammatic. 



FIG. 25. THE IMMUNE SERUM SHOWN IN FIG. 24, AFTER HEATING. 

 The complement is destroyed, and amboceptor only remains. 



FIG. 26. NORMAL SERUM CONTAINING COMPLEMENT, BUT NO AMBOCEPTOR. 



taken to Ehrlich's terms "amboceptor" and "complement," since, 

 as we shall show, they imply a theory, but they are too firmly 

 rooted to be displaced. 



Ehrlich applied his side-chain theory to the study of the 

 phenomena, and argued that amboceptor must be an antibody 

 to the receptors of the red blood-corpuscle. If this is the case, 

 it ought to unite with the corpuscles, and Ehrlich showed in the 



