FURTHIIR Rl:SEARCHi;S IN DlSl-ASES OF Pi. ANTS ^d^) 



md by that I mean experimentally using liis metliods, I am not prepared 

 to admit that he has shown anythins; except presence of the bacteria in the 

 vicinity of the needle wound already known about. However, as I have 

 worked year after year on the crown,i;all and have studied the cancer prob- 

 lem in its larger bearings as it behaves in animal tissues I believe that too 

 much emphasis has been put on the supposed fundamental differences 

 between cancers and granulomas, hi other words, I believe the difference 

 is much less tlian has been supposed and is still supposed by a majority 

 of the workers. 



The intercellular or intracellular location of the bacteria in 

 crown gall is still, even today, under discussion among the most 

 reputable scientific authorities."" Workers do not agree entirely 

 on fundamental points of how " tumor strands " and '" secondary 

 tumors " or " secondary galls " are formed in crown gall."' Crown 

 gall research is. still very much in the foreground of plant scientific 

 research. But the early studies of Dr. Smith and his co-workers 

 are still regarded as " classic " authority, even by those who, on 

 some fundamentals, do not agree with his (or their) conclusions 

 and interpretations. As research facilities have become more ade- 

 quate for the purposes of studying these fundamental phenomena, 

 newly discovered truths and factual data were inevitable. In all 

 branches of science, from generation to generation, this has been 

 so. But no one may deny that Dr. Smith was first to observe 

 these phenomena, to work out proper methods for their study, 

 and to foresee the possible correlations with animal cancer research. 

 A very considerable proportion of his findings as to crown gall 

 has withstood the test of time. Surely his place as the leading 

 pioneer student of this disease in plant pathology is secure. 



During his lifetime, Smith knew that some revisions of his 

 views on crown gall might become necessary. In April 1923 was 

 published from England a paper by W. Robinson and H. Walkden 

 entitled "A Critical Study of Crown Gall." "- Smith read this on 

 June 18, and that night wrote in his diary: 



There is a paper in April Annals of Botany attacking, and perhaps over- 

 throwing, most of my crown-gall hypotheses, which makes me feel very 



"° Riker, Spoerl and Gutsche, Some comparisons of bacterial plant galls and of 

 their causal agents, op. cit., 69-74. 



"^ Armin C. Braun, Development of secondary tumors and tumor strands in the 

 crown gall of sunflowers (review of literature), Phytopathology 31(2): 135-137 f., 

 Feb. 1941; Riker, Spoerl and Gutsche, op. cit., idem. 



"■^-Annals of Botany (London), 37: 299-324. 



