142 THE LYSINS. 



Von Dungern * discovered that epitheliolysins may be produced. 

 His method of experimentation and the results obtained may be 

 briefly stated as follows : He removed the trachea from an ox imme- 

 diately after death, and from this he scraped the ciliated epithelial 

 cells, taking care to avoid mixture with red blood corpuscles or 

 connective tissue. The epithelial cells thus obtained were suspended 

 in physiological salt solution and injected into the peritoneal cavities 

 of guinea-pigs. From time to time some of the injected cells were 

 removed and examined microscopically. The first change observed 

 was one of form, in which the cells were found to be rolled up like 

 balls, but were still capable of moving through the fluid by the ac- 

 tivity of their cilia. Next the epithelial cells were found to be 

 clumped in masses, with the cilia still active and many of these 

 masses were seen moving like an individual through the fluid. 

 Later the cells were seen to undergo a cystoid degeneration. One 

 or more small vacuoles could be seen in the protoplasm, and these 

 often contained leucocytes. These cysts gradually became larger, 

 pressing the nuclei to the edges, and the cells appeared like large 

 vacuoles surrounded by thin walls. From the cavity of an animal 

 treated in this way for the first time visible cells can be obtained in 

 some cases as long as six or even ten days after the injection, but 

 when the same animal is treated after a lapse of ten or twelve days 

 with a second injection of ciliated epithelium the cells are found to 

 bedestroyed with much greater rapidity, and after eighteen hours no 

 eel Is with motion can be discovered. By continuing the immuniza- 

 tion an increased solvent action on the part of the peritoneal fluid 

 was observed. From animals thus immunized to ciliated epithelium 

 there was obtained a serum which in vitro dissolved similar cells. 

 Epithelial-immune serum dissolves the red blood corpuscles as well as 

 the tracheal epithelium of the ox. On the other hand, however, the 

 serum of guinea-pigs immunized to ox blood, has no solvent action 

 upon the tracheal epithelium of the ox, either in vitro or iri'vivo. 

 This phenomenon can be explained in two ways. Either the epithe- 

 lial immune serum contains two lysins, one of which acts upon epi- 

 thelial cells, while the other exerts its effect wholly on the erythro- 

 cytes ; or there may be in the epithelial immune serum only one 

 lysin, which has a specific action on ciliated epithelium and a non- 

 specific action on the erythrocytes. That the latter is the correct 

 explanation is shown by the fact that when immune serum was 

 brought in contact with a mixture of epithelial cells and blood cor- 

 puscles, it acted only on the epithelium. Evidently the lysin in 

 epithelial-immune serum has a greater affinity for epithelial cells than 

 it has for blood corpuscles, and when the former of these is present 

 in sufficient quantity in a mixture of the two, all of the lysin is used 

 up in effecting a combination with the epithelial cells. Von Dun- 

 • Miinehener med. Woehmsehrift, 1899. 



