168 Pathologist U. S. Department of Agriculture 



the end of October displacing Scribner who went to the University 

 and experiment station of Tennessee. 



September 29, 1888, Smith jubilantly wrote to Farlow that 

 "Mr. Galloway talks as though he desires me to continue the 

 investigation." Farlow was then at work on his North American 

 bibliographies of mycological, and later phycological literature, 

 and Smith desired to obtain a copy of part I, Polypetalae, of his 

 and Seymour's Provisional Host-index of the Fungi of the United 

 States, part II, Gamopetalae-Apetalae, of which was to appear in 

 September, 1890, and part III in June, 1891. Sixteen months of 

 continuous research had gone into his preliminary report by the 

 time Smith completed it. Even then, he pointed out as many 

 matters which needed further study as those on which his mind was 

 fairly well made up. He adhered to his theory of a disease caused 

 by a microorganism. He believed he had clearly shown that the 

 disease was communicable and that other prevalently held theories 

 were at least in part discredited. 



The spread of yellows from diseased buds to healthy stocks, which I 

 have carefully verified, points strongly to some contagium vivtim as the 

 cause. . . . Among supposed causes deserving further inquiry I should 

 place root-aphides and root-fungi. I am inclined to believe that neither 

 one is at the bottom of the trouble. ... I can think of nothing else but 

 micro-organisms. ... I write this paragraph with ease, but the work 

 itself is full of difficulties. Nature does not yield her secrets upon the 

 mere asking. . . ?^ 



February 1, 1889, Commissioner Colman commissioned him at 

 a salary of $1,800 a year " to continue his field and laboratory 

 investigation of peach yellows, and to prepare a special report on 

 which particular attention shall be given to the microscopic appear- 

 ances of healthy and diseased tissues, with a view to settle, if 

 possible, the parasitic nature of yellows." 



Smith accepted this commission and early in August had 

 returned to Washington. He began to reside at 229 Eighth Street 

 Northeast and soon was busy at field examinations. Prentiss and 

 other botanists expressed their pleasure on learning of his reap- 

 pointment "to go on with the important work so promisingly 

 begun — on the peach yellows. I hope," wrote the Cornell pro- 



''^ Bulletin 9, Botanical Division, Section of Vegetable Pathology, U. S. Dep't of 

 Agric, 179, 1888; see also. Report on peach yellows, by special agent Smith, 

 Report of the Comm. of Agric. for 1888: 393-398 at pp. 395-396. 



