239 



Iho lissu(> cells in vitro has j^rogressed very greatly; never- 

 Iheless this |)aiiiciilaiiy inleresling and important field has 

 not been studied praclically since that time. To-day when 

 it is ])ossil)le to work willi ])iii-c' strains of several types of 

 epithelium. ril)i'ol)lasts. cartilage, leucocytes and sarcoma 

 cells, the investigation of the cytotoxins should be taken up 

 agaiji. 



Practically any tissue of the l)ody lias l)een studied in 

 respect to their specific cytotoxins, obtained by injecting 

 the various tissue cells into animals of a foreign s])ecies. 

 Leucocytes has been studied by Me t c hn i ko f f 4i4^^ Bes- 

 redka^i''), liver by Delezenne i*^), Deutsch 1*9), kidney 

 by Lindemann -^gg)^ Nefedieff 4i«), Bierry 12)^ Ascoli 

 and Figari •">), pancreas by vSurmont ^^9), adrenal by 

 Bigart and Bernard ^^), thyroid by Ci o u tschar u ko w, 

 Mankowski -^ot^^ heart muscle by (lentanni ^i^). ovarj^ 

 by (leconi and Robecchi ^^l nerve tissue l)y Dele- 

 zenne i-^*^), C. entanni ^i-^). syncytium by Ascoli^), L i e p- 

 m a n n s'^j). 



In order to test the specificity of cytotoxins several 

 methods have been used. Emulsions of cells have been, 

 exposed to the action of immune serum, and the lytic and 

 agglutinative properties were observed. But the lytic and 

 agglutinative properties cannot of course very well be in- 

 dicatives of cytotoxic action, just as little as agglutinins of 

 typhoid bacilli ai*e indicatives of bactericidins. Therefore 

 the technique generally used was to inject the immune serum 

 into the animal body and use the functional or histological 

 changes in various organs, corresponding to the supposed 

 action of the immune serum, as a criterium for the speci- 

 ficity of the cytotoxins. To day the complement fixation 

 would naturally be employed as the proper method. As the 

 technique of making tissue cultures has greatly progressed 

 since that time, we are now able to work with pure strains 

 of the tissue cells, and are able, in a relatively short time, 

 to get plenty of material of pure cells from cultures, enough 

 for the injection into the animals. 



