CYTOLYSINS 143 



tion of these latter cells were called cytotoxins by Metchnikoff, and 

 the name has been retained in spite of the fact that the immune bodies 

 are not toxins in the strict sense of the word but are amboceptors 

 similar to the hemolytic amboceptors. It was thought that cytotoxins 

 might be strictly specific for the antigenic cells of different organs 

 within the same species, but more thorough investigation has shown 

 that such " organ specificity " is not demonstrable. Hemolysins, for 

 example, are lytic for other body cells, such as liver and kidney, pro- 

 vided these cells are of the same species. Hepatolysins and nephrolysins 

 are also active as hemolysins within the species. In other words, 

 these antibodies are species specific but not organ specific. It may be 

 true that a cytotoxin acts more especially on its antigenic organ cells 

 than upon other cells, as is maintained by Pearce for the nephrolysins, 

 but the action is not exclusively upon the antigenic cells. In an ex- 

 tensive study Pearce, Karsner and Eisenbrey were unable to demon- 

 strate any strict " organ specificity " by means of cytolysis, precipitation, 

 agglutination or the anaphylaxis reaction. In this work the organs were 

 washed by perfusion with large amounts of salt solution and thus pre- 

 pared for injection. Bell has pointed out that even the most careful 

 perfusion will not entirely remove the blood from organs and therefore 

 a certain amount of blood must be injected with the other cellular 

 antigen. Nevertheless, the early work of Landsteiner, MetchnikofT and 

 of Moxter showed that spermatozoa which can be obtained free from 

 blood may lead to a spermatolysin which also acts as a hemolysin. The 

 amount of blood injected with carefully- washed organs is so small 

 that it can have but little antigenic power, too little to be consistent with 

 the well-marked hemolytic power of the cytotoxic sera. Recently, 

 however, Wilson and Oliver have absorbed the hemolysin from cyto- 

 toxic sera by means of erythrocytes and maintain that there is a very 

 definite organ specific cytotoxin contained in nephrolytic serum pre- 

 pared by immunizing with kidney substance. This specific nephrolysin 

 can be removed by absorption with kidney substance but not with other 

 organs. If these studies are extended and confirmed, much new light 

 may be thrown on the subject of organ specificity. 



In spite of the apparent lack of strict organ specificity, the cytotoxins 

 of certain types of cells deserve mention, namely those resulting from 

 the injection of leucocytes and of crystalline lens. Following a brief 

 communication by Delezenne concerning leucotoxins, Metchnikoff 

 studied the matter by injecting guinea-pigs with material from the 

 mesenteric lymph-nodes and from the bone marrow of rabbits. The 

 resulting immune serum was highly toxic for guinea-pigs, but if given 

 in sufficiently small doses produced first a marked leucopenia, fol- 

 lowed in several days by a leucocytosis. This was confirmed by others 

 who used for injection also leucocyte emulsion, and although species 

 specificity was strict, the cellular specificity was not. Lucatello and 

 Malon were able to obtain a serum by the use of leucocytes from cases 

 of leucemia and treated a series of cases with this serum. The leuco- 

 cytes were reduced in number and the spleen diminished in size, but 



