1 82 MARRIAGE AND DISEASE. 



doubtless many elements of unhealth combined in its 

 evolution. 



Latterly the opinion has been expressed by some 

 that cancer probably depends upon some micro- 

 organism, and this, I believe, will ultimately prove to 

 be true. In 1887, Scheuerlen, of Berlin, announced 

 that he had discovered a bacillus peculiar to cancerous 

 growths ; but closer investigation proved fatal to the 

 discovery. Professor Virchow found the same micro- 

 organism growing upon sections of 'potato which could 

 not have been contaminated from any cancerous tissue. 

 Nevertheless, this appears to be the most promising 

 direction for investigation, and it is not at all impro- 

 bable that ere long cancer may be found to depend 

 upon the presence of some micro-organism; which 

 discovery, when made, will in no way aifect the theory 

 of the hereditary character of the disease. 



Predisposition must exist in nearly every case in 

 which cancer occurs. It is by no means unusual for 

 cancer to follow local injuries to tissues or organs. 

 A blow upon the breast will often be found the start- 

 ing-point of a cancer in woman, and the irritation 

 caused to the lips by the continued use of a clay pipe, 

 or to the tongue by decayed teeth, is frequently given 

 as the cause of the disease. But such injury or irri- 

 tation can only be the exciting cause, else thousands 

 more than are at present would be the victims of 

 cancer. How many thousands receive injuries to the 

 breast, smoke clay pipes, and have their tongues irri- 

 tated by broken teeth without result? Those who 



