SPECIFIC FERMENTS OF THE CANCER CELL 425 



tion is labored and, when death ensues, always stops before 

 the heart-beat. Rabbits which die from a dose, after being 

 sensitized, usually have a stage of apparent rest from one- 

 half to three hours after the first stage of excitability, which 

 lasts for from three to five minutes. A possible explanation 



FIG. 29. Rabbit given a single 

 intraperitoneal injection of cells 

 from a breast adenocarcinoma. 



FIG. 30. Rabbit injected with 

 a breast-cancer residue which has 

 almost lost its activity. 



of this is that the first stage of excitement is due to the 

 destruction of cancer cells and consequent liberation of 

 their toxic radical by the specific ferment present in the 

 blood serum, while the fatal result which follows later is 

 due to the reaction between the cancer cell and the large 

 mononuclear leukocytes. 



