294 INFECTION AND IMMUNITY. 



sorption of the adventitious amboceptors by means 

 of the corresponding cells. Inasmuch, however, as 

 the result is a decrease in the chief amboceptors 

 as well as of the adventitious, the desired object is 

 not fully realized. Theoretically the cytotoxic 

 treatment of malignant tumors offers an impor- 

 tant field for research. But here, too, various dif- 

 ficulties are involved, as lack of specificity of 

 serums and the multiplicity of cell-types which 

 constitute different tumors. 



Experiments with cytotoxic serums may be con- 

 ducted in vitro or in the living animal. In either 

 case a necessary condition for the recognition of 

 the cytotoxic action is the presence of some dis- 

 tinctive sign of vitality on the part of the cell, the 

 loss of which may be taken as evidence of cell- 

 death. Loss of motility and of proliferative power 

 indicate the death of bacteria, and solution of 

 hemoglobin the death of erythrocytes. Under par- 

 ticular conditions loss of motility on the part of 

 certain tissue cells, as spermatozoa, leucocytes and 

 ciliated epithelium, is an evidence of cell death or 

 cell injury. The toxic action of serums on cells of 

 fixed form is more difficult to determine, and for 

 evidence one must rely on such points as clearing 

 of the protoplasm (digestion?), swelling of the 

 cell and nucleus, actual solution of the cytoplasm, 

 or degenerations of the homologous organs when 

 the serum is injected into the living animal. 



technic of immunization with tissue cells is 



of 

 immunization similar to that of immunization with bacteria. In 



order to obtain leucocytes in abundance, artificial 

 leucocytosis is produced in the peritoneal or pleural 

 cavity by the injection of bouillon, or lymph 



