StudiI'S on Crown Gam. of Plants 437 



gall, where occurring, he said, is a plant cancer, structurally 

 " unlike that of dub-root of cabbage, which is a hypertrophy rather 

 than a hyperplasia." "'-' The olive tubercle {Bacterium savastatwi) 

 was "' an excellent example of atrophy.""^ In suggesting resem- 

 blances in crown gall of plants to malignant animal tumors and 

 certain malignant neoplasms in man he hoped to aid animal and 

 medical pathologists in solving problems of the more obscure 

 higher animal malignancies including human cancer. It is true 

 that he consistently favored the view that in certain types of 

 human cancer a parasite would be found involved, indeed the 

 cause. But in his 1912 bulletin, "" The Structure and Development 

 of Crown Gall," he made it plain that nothing therein should be 

 construed to indicate that the authors, Smith, Miss Brown, and 

 Miss McCuUoch, believed that " the organism causing crown galls 

 is able also to cause human cancer, but only that [they believed] 

 the latter due to a cell parasite of some sort . . .," *'' and the 

 possibility of a virus origin of human cancer was not excluded. 

 If a tag must be affixed. Smith preeminently was a physiologist 

 in plant pathology or a pathologist in plant physiology, interested 

 in studying the life processes and structures, and the existent 

 analogies, between created living forms, the intention being to 

 help solve the problems of disease. He grew bolder as he grew 

 more convinced. But in his first appearances before the American 

 Association for Cancer Research, he maintained little more than 

 his fundamental contention: that crown gall of wild and culti- 

 vated plants, while proved conclusively to be of bacterial origin, 

 is a tumor growth, comparable to certain malignant animal tumors. 

 February 22, 1909, William Carpenter MacCart}% associate path- 

 ologist of the laboratory staff of the Doctors Mayo, Graham and 

 Company — the renowned Mayo Hospital — of Rochester, Minne- 

 sota, addressed a letter to Smith: 



Your letter of February 18th and reprints were received and thoroughly 

 appreciated. 



My scientific career was started as a botanist, and I therefore seek on 

 every occasion to connect histological botany with histological pathology. 



I have for some time wondered whether there could be any facts con- 



'^^ Idem, 57, fact 5. See Resume, pp. 57-60; 38 facts summarized. 

 "B^f/. in Rel. to PL Dis., op. cit., 2: 92. 

 " Op. cit., fact 38, p. 60. 



15 



