648 Third European Journey 



pathologist of the London Imperial University, called while on 

 his way to the American cotton belt regions. American botanists, 

 too many to list all, continued to visit the laboratory, some to 

 examine scientific materials and some for consultations. During 

 these years, a noticeable increase of correspondence with Canadian 

 scientists took place: mostly with botanists, however, interested 

 in the crown gall-animal tumor work. 



Dr. Charles Mayo, in whose company Dr. Smith had gone to the 

 cancer symposium at Lake Mohonk, spent an hour or two at the 

 laboratory on January 14, 1927. So interested was he still in 

 Smith's work that, like other doctors at other hospitals, he had 

 sent both surgeons and medical practitioners to inspect his 

 materials. The importance of the laboratory's work was particu- 

 larly recognized in other scientific laboratories of Washington. 

 For instance, within a little more than a month's time in 1926, 

 three pathologists from Garfield Hospital in the company of Dr. 

 Garner, and Professor Treat Baldwin Johnson of Yale University 

 with Dr. William Charles White of the Hygienic Laboratory, 

 visited Smith's laboratory. Dr. Johnson was planning to do some 

 work in organic chemistry on crown gall. As promised, Dr. Koitchi 

 Itchikawa on May 25, 1925, made a trip from New York to 

 Washington for the sole purpose of examining Dr. Smith's plant 

 tumor collections, and was given slides and specimens, and cultures 

 later. On January 25, 1926, Jensen of the experiment station at 

 Copenhagen, Professor Hurdon of the Rothamsted station, and Dr. 

 B. M. Duggar, called. March 16 Miss Wilbrink arrived from 

 Holland after having been since September in the Dutch and 

 English West Indies, and was entertained by Dr. Smith and his 

 laboratory assistants. Visitors from all parts of the world made 

 a point of seeing the laboratory before returning to their native 

 lands. At times one countryman would tell a fellow scientist of 

 work seen. For example, from Sweden in 1922 had come Professor 

 Barthel, director of the central agricultural stations and depart- 

 ment of agricultural bacteriology, and three years later, on Novem- 

 ber 27, Dr. Lundegardh, pathologist interested in destructive soil 

 parasites including Fusariums, spent a good part of the day with 

 Dr. Smith. Before and after the Ithaca congress, many foreign 

 scientists visited his laboratory. Nils Svedelius of Uppsala, student 

 of marine algae, among them. Olof Arrhenius, son of the great 



