496 Second European Journey 



and fugitive blossom buds." It was possible, furthermore, " to 

 inoculate tobacco plants so as to obtain tumors with no shoots." 

 On August 9, Smith answered a letter from Dr. Charles H. 

 Mayo: 



Permit me to congratulate you on your election to the presidency of the 

 American Medical Association. It is a high honor and one well deserved. 

 I am getting some wonderful results this summer with my teratoid crown- 

 galls, photograph of one of which I enclose. The needle pricks were made 

 in the cut end of the stem (main axis of the plant) and you will see that 

 a good sized tumor has developed, covering the whole top of the plant, 

 and sprouting from various parts of it are dozens of embryonic fragments 

 (diminutive tobacco plants). ... I have a dozen other plants in the houses 

 at the present time with tumors as strange as the one shown. ... I am 

 working mainly at present with tobacco, castor oil bean, and the common 

 red house geranium. The same sort of tumors can be produced, as I now 

 know, on many other plants. I am slowly gathering material in the shape 

 of notes and good photographs for a special paper on atypical teratomata 

 in plants due to bacterial inoculation. I am working also on the chemical 

 end of the subject this summer and have obtained some quite interesting 

 and very striking results, which will I hope form a basis of another 

 paper. . , . 



In June 1917 Dr. Mayo, in his presidential address,^- gave Smith 

 the following splendid recognition: "We are proud of our agri- 

 cultural department and its investigations as to the causes, control 

 and cure by serums of the diseases of animals and the destruction 

 of parasitic hosts. The work of Erwin F. Smith on plant diseases 

 is monumental, especially his discoveries as to the causes of certain 

 plant tumors. . . ." 



One month before, April 1917, in Proceedings of the National 

 Academy of Sciences,^^ had been published Smith's communication 

 of the previous January 26 to the Academy, entitled, " Chemically 

 Induced Crowngalls." In the January 29 issue af the Journal of 

 Agricultural Research " had appeared Smith's even more important 

 study, " Mechanism of Tumor Growth in Crown Gall." Previous 

 to these, moreover, in the October 27, 1916, number of Science *'^ 

 Smith's report on plant tumors formed by products of bacterial 

 growth, '" Tumors in plants," had excited wide attention. Reprints 



^' Jour. Amer. Med. Ass. 68(23): 1675, June 9, 1917. 



'^3: 312-314, Apr. 1917. 



^*S0): 165-184, Jan. 29, 1917. 



«' 44(1139): 611-612, Oct. 27, 1916. 



