HYPERBLASTOSIS AND MALIGNANCY 349 



suggests strongly that the causation of malignancy is not to be 

 sought for in the entry and action of external agencies, but in 

 stimulation of the growth properties of specific tissues by changes 

 in what I may term tissue equilibrium. And lastly, that the 

 more we study, the more we become impressed by the fact that 

 the number of conditions of hyperblastosis, whether simple or 

 malignant, is relatively considerable, so considerable as to 

 deserve separate consideration. 



