506 Second European Journey 



supplied Dr. Clowes with tumor and gall materials on sugar 

 beet, Pelargonium, tobacco, and hop. An exchange of letters 

 indicates that these plant materials were used in experimental 

 work aimed at " determining the relative permeability of the 

 tumor and normal tissues under normal conditions and under the 

 influence of the various agents brought to bear on them." Dr. 

 Clowes explained on April 2 that he was " making conductivity 

 and permeability determinations on the materials ... in com- 

 parison with cancerous and normal tissues derived from mice and 

 human beings. Also the influence of electrolytes on the equi- 

 librium of the tissues in question." Many doctors, students of the 

 cancer problem in one capacity or another, sent Smith letters 

 assuring him of their interest in his studies and the high value 

 they placed on his research results. Students of such calibre as 

 Dr. J. Collins Warren, professor emeritus of surgery at Harvard 

 Medical School, Dr. Douglas Symmers, pathologist of Bellevue 

 Medical College, Dr. Stanhope Bayne-Jones, pathologist and bac- 

 teriologist, Dr. Theodore C. Janeway, physician-in-chief of Johns 

 Hopkins Hospital, Dr. Walter C. Burket of Johns Hopkins Medical 

 School, and Dr. John J. Abel of Johns Hopkins's department of 

 pharmacology were among many others and reveal the range of 

 various scholarly work to which the studies had some pertinence. 

 Such leaders as Dr. Flcxner, Dr. Hurd, Dr. Keen, Dr. Cushing, 

 Dr. Prudden, and Dr. Cullen continued to express their apprecia- 

 tion and belief in the value of Smith's studies. Indeed, Dr. Warren 

 wrote that the crown gall studies were " of the greatest interest 

 to those engaged in the cancer problem," and Dr. Burket told 

 Smith, " as Pasteur approached the question of infectious diseases 

 thru fermentation so you may approach the great problem of new 

 growth and cancer thru your studies in plant tumors." 



Biologists also were interested. In 1916 Director C. B. Daven- 

 port of the department of genetics of the Carnegie Institution 

 and the Station for Experimental Evolution at Cold Spring Harbor 

 read Smith's " Studies on the Crown Gall of Plants its relation to 

 human cancer " and began an exchange of letters. In February 

 1917 he answered a letter from Smith and expressed his delight 

 that he had " succeeded in producing the small plant tumors in 

 the absence of many of the bacteria. This brings," he said, " the 

 phenomenon in plants in closer relation to that in animals." The 



