On Tmmiinity loith Special Reference to Cell Life. 



447 



certain animal species, and are much more inconstant in their action 

 than are the antitoxines. Sobernheim, in the laboratory of C. Fraenkel, 

 found that the anthrax serum obtained by immunising German marmots 

 (Hamster) protected this species, even in small doses ; but was abso- 

 lutely without action for rabbits. Kitt had a precisely similar 

 experience with symptomatic anthrax. This circumstance is easy to 

 understand, if the complex nature of the lysines be borne in mind. 

 The lysine, be it bacteriolysine or hsemolysine {i.e., " immune body " 

 + " complement "), possesses altogether three haptophore groups, of 

 which two belong to the "immune-body" and one to the "comple- 

 ment." Each one of these haptophore groups can be bound by an 

 appropriate "anti-group." Three anti-groups are thus conceivable, 

 any one of which, by uniting with one of the haptophore groups of 

 the lysine, can frustrate the action of the lysine. To my mind, of these 

 three possible " Antikorper," that one which can lay hold of the hapto- 

 phore group of the " complement," and so prevent this from uniting 

 with the " immune" body," is the most important. Dr. Morgenroth and 

 I have experimentally succeeded in producing such bodies by processes 

 of immunisation, and in proving that they unite with the " comple- 

 ment " (anticomplement). 



Dr. Neisser at the Steglitz Institute sought to find an explanation of 

 Sobernheim's experiments. He was able to determine that anthrax 

 serum failed in mice, even if great quantities of fresh sheep's serum 

 {i.e., containing excess of "complement") were at the same time intro- 

 duced. The failure in this case appears to be due, on the one hand, to 

 the destruction, in the body of the mouse, of the "complement" 

 present in the sheep's serum, and, on the other hand, to the fact that 

 the " immune body " yielded by the sheep does not find in mouse serum 

 an appropriate new " complement." 



From this it appears, that in the therapeutic application of anti- 

 bacterial sera to man, therapeutical success is only to be attained if 

 we use either a bacteriolysine with a " complement " which is stable in 

 man (" anthropostabile complement "), or at least a bacteriolysine, the 

 " immune body " of which finds in human serum an appropriate " com- 

 plement." The latter condition will be the more readily fulfilled the 

 nearer the species employed in the immunisation process is to man. 

 Perhaps the non-success which as yet has attended the employment of 

 typhoid and cholera serum will be converted into the contrary if the 

 serum be derived from apes and not taken from species so distantly 

 removed from man as the horse, goat, or dog. However this may be, 

 the question of the provision of the appropriate " complement " will 

 come more and more into the foreground, for it really represents the 

 centre round which the practical advancement of bacterial immunity 

 must turn. 



A second and at present much-discussed question is the immunising 



VOL. LXVI. 2 M 



