THE RECURRENCE OF CANCER 397 



rectum, the very place where one would expect it to 

 occur. Now that we know the causes of cell-prolifera- 

 tion it is difficult if not impossible to believe that a 

 metastatic growth could remain malignant and quiescent 

 for ten years without proliferating. We think that the 

 increase of "restraining body" conferred on a person by 

 a malignant growth may not last very long, and this, 

 coupled with advancement of old age and possibly the 

 existence of physiological excess of general aiixetics 

 which may occur in some persons, may predispose them 

 to subsequent attacks of cancer. Our argument is that 

 cancer is due to a combination of physiological auxetics 

 and pathological alkaloids of putrefaction. The combi- 

 nation must be a definite one, or it will not be effectual ; 

 it must diffuse into the cells to a certain extent for a 

 Certain length of time, with due regard to the coefficient 

 of diffusion of the cells; and lastly the vitality of the 

 cells themselves must not be greatly impaired. We 

 think that unless all these factors are in correct combina- 

 tion, malignant disease cannot occur. 



With regard to the cause of sarcoma, we think that 

 it is probable that the auxetic chiefly concerned in that 

 disease is that contained in globin. Several 'surgeons 

 haVe kindly informed us that in almost every case of 

 sarcoma which they have seen there is .a history of 

 injury; and it is remarkable that sarcoma occurs .most 

 frequently in those tissues which are rich in hsemo-' 

 globin, namely, the choroid coat of the eye (melanotid 

 sarcoma), the bone marrow, and the neighbourhood of 

 muscles. The suggestion that globin is the source 

 of the auxetic in sarcoma will explain the age-incidence 



