568 Crown Gall-Animal Cancer Analogy 



me give you a word of advice. It always takes two to make a 

 quarrel." ^°° 



The next day Smith attended a conference of fifty-five plant 

 pathologists on extension work. He thought them " splendid 

 fellows, mostly young. Very eager to help the farmers." He 

 himself was approaching the retirement age. Under the pro- 

 visions of the Retirement Act of May 22, 1920, he in 1924, after 

 thirty-seven years with the Department of Agriculture and at the 

 age of seventy, could retire from active scientific service. He 

 would choose, however, to apply for a two-years extension, and, 

 at a salary of $5,500 a year, the extension would be granted. His 

 laboratory of plant pathology possessed a personnel of eighteen 

 employees and he, as its chief, supervised an annual expenditure 

 of approximately $52,460. In July 1922 he had explained one of 

 his main reasons for his perseverance: " if I," he said, " succeed 

 in turning the tide of cancer research into biological channels 

 I shall be more than repaid." In 1923 Smith was unable to get 

 at his crown gall researches again until late in January. He tried 

 to begin work on a " revision and completion of [his] ms. for 

 Volume IV of [his] Carnegie monograph," Bacteria in Relation 

 to Plant Diseases. " I shall never complete it if I don't get going," 

 he commented in his diary. " There is a good half-year's work 

 on it, and perhaps more." 



His attitude toward Riker's papers was one of awaiting further 

 scientific proof. On May 14, 1923, he acknowledged receiving 

 from Professor Etienne Foex of the Station de Pathologic Vegetale, 

 Paris, France, some specimens of diseased tobacco leaves, two 

 letters, and a paper by Foex which summarized Smith's studies on 

 crown gall. " Concerning Riker's work," Smith wrote, 



it is as yet only in the "' dough," so to speak, and we must wait for a full 

 paper before any decision can be come to and probably not then. I heard 

 his paper . . . and at that time pointed out that he had not shown any- 

 thing which we did not already know, namely, in the needle wound and its 

 vicinity, that is as far as the wound exudate is spurted when the needle is 

 driven in, there, of course, the bacteria will be carried and found. This does 

 not, I think, explain what we have had very often, namely, the occurrence of 

 secondary tumors at a long distance from the primary tumor in leaves 

 already fairly well developed when the needle prick was made in the stem 

 below the leaf. Until we have ourselves gone over Riker's work critically, 



' Told author by Dr. Riker. 



