236 Early Studies in Bacterial Plant Diseases 



existence of the inciting cause of the disease as either an external 

 parasite or as internal and cumulative." Therefore, how to elimi- 

 nate the parasitic cause? During the summer of 1892, Pierce 

 prepared a paper in the belief that the disease known as coulure 

 eventually would have to be conquered in the light of Millardet's 

 work on hybridization of the vine. He wrote Galloway to ask 

 whether he should not append a copy of the translation to his 

 paper. "As you of course know," he told Galloway, " Millardet's 

 work has been with the object of obtaining a vine or vines which 

 shall be resistant to the more important diseases and yet retain 

 good fruit-producing qualities. It is not at all unlikely that it will 

 be along this line that the trouble of coulure will eventually have 

 to be conquered. . . ." This letter was dated July 18, 1892. Gallo- 

 way read Millardet's paper, approved its translation, suggested 

 Millardet might revise and add to the text, sent a few references 

 on fertilization of grapes, explained that other Departmental pub- 

 lications than Pierce's vine disease report had been similarly 

 delayed, and that he, as much as anyone, awaited with pleasure 

 the printed volume. That summer Pierce gave much time to 

 studying the souring-of-figs disease. Alike for this and the grape 

 trouble he planned to go to Fresno. He was sure that in 1888 

 Emerich Rathay had published in Vienna a paper, " Die Gesch- 

 lechtsverhaeltnisse der Reben," which contained much valuable 

 information on vine fertilization and the vitality of pollen which 

 might prove helpful in his coulure investigation. He inquired of 

 Galloway whether there was a copy of it in the Department's 

 library or whether he would have to order it from Berlin. Ob- 

 viously, he was working on his valuable achievement of 1892 — 

 the production by hybridization of disease-resistant vines which 

 bore " superb bunches of fruit of excellent quality. Mr. Pierce's 

 first crosses," later ^^ wrote Smith, "were made according to my 

 recollection in 1892. Mr. Pierce also successfully crossed raisin 

 grapes to resist coulure, a disease which renders the bunches ragged 

 and worthless for market by causing the abortion of the whole or a 

 large part of the berries when they are very small." 



Galloway reported in 1893 that Pierce had shown that coulure 



^^ Plant breeding in the United States Department of Agriculture, Royal Horti- 

 cultural Society's Report of the Conference on Genetics — 1906, reprint, 303, 1907. 

 See also Fifty years of pathology, op. cit., 22. In that address. Smith, without 

 qualification, gives the year as 1892. 



