1906.] Specificity and Action in Vitro of Gastrotoxin. 437 



the serum, and therefore of rendering it incapable of dissolving the red-blood 

 corpuscles of the guinea-pig in vitro. Occasionally, especially in the case of 

 the liver, a slight amount of diffused haemoglobin may be seen above the 

 settled corpuscles. 



These experiments clearly indicate that although the hcemolytic factor of the 

 gastrotoxic serum may be of great importance in assisting to produce the 

 stomach lesions in vivo, yet it is not the only one. The reasons for this state- 

 ment are, that previous mixture with stomach cells will deprive the serum of 

 its action in vivo, but will not prevent its laking blood corpuscles in vitro ; 

 that previous mixture with liver cells, intestine cells, or red-blood corpuscles, 

 although it deprives the serum of its power to lake blood corpuscles in vitro, 

 will not with any degree of uniform certainty completely prevent its action 

 in vivo. 



Lysin, — I have not yet attempted to compare the gastrolytic strengths of 

 two sera by determining the highest dilutions in which any action is apparent, 

 and therefore cannot say whether or not the action in any given case is 

 diminished. So far as my results go, however, they appear to indicate that, 

 after exposure of the serum to gastric cells, its action upon such cells is 

 destroyed, but that after exposure to liver and intestine cells and blood 

 corpuscles the serum still produces changes in gastric cells in vitro. 



These in vitro experiments, so far as they go, point to the same conclusion 

 as the in vivo experiments — namely, that this gastric cytotoxin is not truly 

 specific, although one or more of the bodies contained in it may be so, and 

 that the protoplasmic poisons constituting it have a greater affinity for gastric 

 cells than for the cells of other organs of the body. 



2. Comparison with Hepato- and Entcrotoxic Sera and Hemolysin. 



The hepatotoxin and enterotoxin were respectively prepared by injecting 

 the rabbit with the washed and prepared cells of the liver and intestine of 

 the guinea-pig. The hemolysin was obtained by injecting red-blood 

 corpuscles. 



Experiments in Vivo. — Each of these sera produces haeinolytic lesions in the 

 stomach, leading to destruction of the mucous membrane, the microscopic 

 condition very closely simulating that due to gastrotoxin (see Plate 17, fig. 7). 



They are more uncertain in their action upon the stomach, however, and 

 this action is liable to be not so strictly limited to the stomach as that of 

 gastrotoxin. The action of haeinolytic serum was described in my previous 

 communication. 



Experiments in Vitro. Hcemolytic Power. — Both hepato- and enterotoxin 



