1906.] Specificity and Action in Vitro of Gastrotoxin. 439 



The normal serum of the rabbit is slightly hemolytic for human blood 

 corpuscles, but does not produce any effect upon emulsions of human 

 stomach granules. 



1 have succeeded in showing that the sera of five rabbits so immunised 

 became highly hemolytic for human blood corpuscles, and in the one case 

 in which T tried it, solution of the corpuscles of the monkey also occurred. 

 The sera also agglutinated and precipitated emulsions of human gastric 

 granules, and in one case those of the monkey also. Whether hyaline changes 

 are produced in the cells I have not yet determined. 



IV. General Conclusions. 



The gastric cytotoxin formed in the blood of an animal in response to the 

 injection of gastric cells thus appears to be a complex body. After a single 

 injection there is a great increase in the hemolysin normally occurring in 

 the animal's blood, and at the same time there is found a new haemolytie 

 immune body which is not normally present in the animal. The latter is 

 present in considerable amount after the second injection. The gastrotoxin 

 also agglutinates red-blood corpuscles. Closely associated with the appear- 

 ance of this artificial haemolytie immune body is that of an agglutinin which 

 acts upon the gastric granules, and also that of a precipitin which acts upon 

 the soluble proteids of the gastric cells. 



By repeating the injections these substances are found to be present in 

 the blood for several months. Whether they are one and the same or distinct 

 bodies I have not yet proved. 



After several injections, and not less than about five weeks from the first, 

 a further substance appears in the blood, which possesses an action upon the 

 intact gastric cells. In spite of repeated injections, this substance disappears 

 from the blood in about four months. It is probably of the same nature as 

 a hsemolysin, but this point requires proof. 



The haeruolytic factor is only active against blood. The actions of the 

 agglutinin and precipitin are not confined to the constituents of the gastric 

 cells, but extend to other proteids of the body. Whether there are separate 

 agglutinins and precipitins for different proteids, or whether the same 

 substances act upon all proteids, has not been determined ; at all events, 

 if the same bodies are concerned in all cases, their action upon the proteids 

 of the stomach cells is probably greater than that upon other proteids. 



Whether the gastrolysin itself is truly specific remains to be proved. 



The few experiments that have been undertaken in the case of the human 

 stomach indicate that the human gastric cytotoxin is identical in constitution 

 with that of the lower animals. 



