570 Crown Gall-Animal Cancer Analogy 



humble; but if I could not make the discoveries they report (which con- 

 firm Riker's) I have at least stirred up others to do so, and there are some 

 things I must see for myself before I shall be convinced. Probably my 

 desire to help in the solution of the cancer problem has led me to over- 

 stress phases of the interpretations, and anyway the hundreds of clear-cut 

 experiments remain whatever the conclusion drawn from them. Next I am 

 going to study the Potentiometer reactions of the crown-gall tumors and 

 after" that I will try to produce tumors out of single cells by means of the 

 Barber apparatus. 



It may be added now that Dr. Smith did not change his views 

 on crown gall research during the balance of his life, although, 

 as we shall see, he continued to study points concerning the 

 " tumor strand," the " secondary tumor " and location of the 

 bacteria in crown gall throughout his remaining years. For the 

 time being, however, this must end our consideration of this 

 subject. In February 1925, while visiting at the Pasteur Institute, 

 he would defend Riker's skill as a careful scientific workman, and 

 more, he would recommend Riker to the International Education 

 Board for a year's study abroad when, among other places, he 

 and Mrs. Riker would study at the Pasteur Institute. 



The new papers of, first, Dr. Riker, and then, Robinson and 

 Walkden, v/ere published after Dr. Smith presented his address 

 on " Twentieth Century Advances in Cancer Research " but before 

 the address v/as published. He did not delete his quotation from 

 Dr. E. J. Butler's London Lancet "^ paper, " Some Relations be- 

 tween Vegetable and Human Pathology," in which was mentioned 

 the " extreme difficulty of detecting the parasite in the cells." To 

 his parenthetical comment, "it is certainly in, not between the 

 cells," Smith, presumably, suffixed a footnote: "Recently Riker 

 in the United States and Robinson and Walkden in England have 

 denied this, maintaining that the organism is always between the 

 cells. . . ." In August of 1921, Dr. Butler, then in America, had 

 spent four hours with Smith at his laboratory, and had been 

 shown " many specimens and many stained slides." For nineteen 

 years he had served as a plant pathologist in India, at Pusa, and 

 was now Director of the Imperial Bureau of Mycology or plant 

 pathology at Kew. Smith first saw his paper on May 18, 1922, 

 and saicl of it in his diary: 



"''Jan. 21, 1922, p. 160. 



