SITE-INCIDENCE 363 



the right combination, for we have shown that alkaloids 

 by themselves are not effectual in inducing cell-division. 

 On the other hand, after the age of 40 the slight 

 physiological increase in the quantity of auxetics 

 present in a tissue, owing to excess of products of 

 katabolism, may just supply the required quantity of 

 auxetic to produce the right combination between 

 them and an alkaloid, should the latter be present. 

 It has already been suggested that the onset of 

 cancer may be partly due to the oversetting of a 

 normal balance. 



In connection with this point we would recall the 

 fact that cancer seems to attack persons who are 

 prematurely aged, especially those who are subject to 

 such diseases as the atrophic form of osteoarthritis 

 a fact which seems to bear out this explanation of the 

 age-incidence of cancer. 



Conversely, it has been shown that cells with a 

 lowered vitality require more of an auxetic to produce 

 cell-division in a given time than normal cells; and 

 this may explain why cancer does not so commonly 

 occur in the aged and infirm, for although the right 

 combination of the cause of the disease may be present, 

 it is not present in sufficient strength to produce 

 malignant proliferation in cells which have lost their 

 vitality to some extent. 



The suggestion that cancer may be due to putre- 

 factive decomposition of the remains of dead tissues 

 in a chronic healing site will harmonise with the fact 

 that cancer occurs commonly in certain sites. Carci- 

 noma occurs most frequently in the breast, uterus, 



