46 WARFARE IN THE HUMAN BODY 



these results it can hardly be thought that any specific 

 cancer protozoon continues to live. Those who believe 

 in the infection theory must take up the position that the 

 agent is everywhere in the body or the environment ready 

 to infect the patient in the so-called pre-cancerous stage 

 of X-ray malignancy. Such a hypothesis is a multi- 

 plication of causes. The only true pre-cancerous stage is 

 seen when the underlying connective tissue weakens or 

 rarefies. This is assuredly the case in leucoplakia, although 

 I have not so far been able to see sections proving it. 

 The destructive powers of the X-rays on connective 

 tissues, in combination with the resistance of the skin, 

 are sufficient to account for the results. In what other 

 way can we interpret the conclusions reached by J. B. 

 Murphy and Sturm ? These workers found that the 

 entire lymphoid tissue of the body could be destroyed 

 in from seven to twenty-one days by repeated small doses 

 of X-rays. In such a condition the theory of this paper 

 would infer that an immense reduction of organic resist- 

 ance followed. What do we find ? First, there is a greatly 

 lessened resistance to alien implants ; second, a lowered 

 resistance to cancer grafts ; third, the destruction of 

 acquired immunity to cancer ; and, fourth, a lowered 

 resistance to the tubercle bacillus and other infective agents. 

 Murphy, however, remarks that the chief objection to 

 accepting the lymphatics as a great factor of resistance to 

 cancer growth is that the lymph nodes are common points 

 for metastatic growths. This appears to be no such 

 objection as he imagines since the very existence of the 

 primary focus is in all probability due to general loss of tone 

 of all connective-tissue cells, stationary or wandering, 

 highly evolved or semi-embryonic. I draw the con- 

 clusion with confidence that, as with chorion-epithelioma, 



