RiiSLAKLii ON Plant Tumors 405 



That botanists as well as zoologists and physicians saw Smith's 

 experimental materials, and were impressed, seems evident from 

 a letter written h\ John Merle Coulter to Smith after the meetings 

 of the National Academy: 



It was a great pleasure to meet you aqain in Washington, and particularly 

 to see your material. I did not get in to iicar you present it at the meeting, 

 chiefly because I had had a more satisfactory demonstration in connection 

 with the plants themselves. I heard, however, that the fifteen minutes left 

 at your disposal were about the best received fifteen minutes of the program. 



The elderly Dr. William Williams Keen, president of the 

 American Philosophical Society, author of the six — later eight — 

 volume Keen's System of Surgery, and one of the truly great 

 figures of medical history, wrote on May 29, 1916: 



Thank you for supplementing my very interesting thoucjh too brief visit 

 with you recently in your greenhouses. The work that you have done on 

 the pathology of cancer in plants is very extraordinary. 



I shall hope very sincerely that our Committee may be able to arrange 

 with you for a paper at the General Meeting of the American Philosophical 

 Society next April when you would have an audience of about one-hundred 

 scientists from all over the country. A paper at that time I should hope 

 would contain the tjetf matter that you have accumulated of late as we 

 always desire, of course, for the these General Meetings in April papers of 

 original research as far as possible. 



Smith replied on August 10: "I am finding my experiments 

 so interesting this summer that I doubt if I shall be able to get 

 in a vacation until some time in the fall. I am obtaining very 

 wonderful results with the teratoids and also by direct chemical 

 stimulation. I now think I shall be able to demonstrate chemical 

 stimulus." 



He enclosed a photograph of a tumor " produced in the top 

 of a tobacco plant by a pure-culture inoculation (needle pricks 

 only), the top being cut off in the middle of an internode and 

 the pricks made into the cut surface. An irregular tumor covering 

 the whole top [had] developed and out of this dozens of young 

 leafy shoots [were] growing." Except when inoculated, such cut 

 stems never developed growths. " If the inoculations are made 

 toward the base of the plant," he said further, " I get only leafy 

 shoots; if they are made well toward the top of the plant just 

 before blossoms develop I get tumors containing both leafy shoots 



