418 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1914. 
German and Scotch breeders in securing disease resisting potatoes 
is fully recognized.t The work started by Ward at Cambridge has 
raised our hopes relative to the possibilities of placing the studies of 
disease resistance on a scientific basis. The most stimulating results 
in America have dealt with resistance to soil fungi including Orton’s 
work on cowpea, cotton and watermelon in the South, and Bolley’s 
work on flax in Dakota. Such results as these and Norton’s on 
asparagus rust resistance are to be regarded, not as final, but as merely 
suggestive of what I believe to be the most important future line of 
work in the control of plant disease, the breeding and selection of 
plants for local adaptation and disease resistance. If this is true 
then the fundamental problem deserving most serious consideration 
is, What constitutes disease-resistance? The difficulty of even 
defining the factors involved should not deter us from urging its 
importance and encouraging work upon it along all possible lines of 
attack. 
IX.— CONCLUSION. 
In conclusion let us emphasize that, if progress in plant pathology 
is to continue as rapidly as we hope, those who are responsible for its 
direction should realize the limitations of the individual workman, 
and the necessity for division of the labors involved. 
The demand to-day upon the American phytopathologist is almost 
equally urgent for four types of service—(1) college teaching, (2) 
extension teaching, (3) inspection, (4) research. In how far are these 
compatible ? 
The ideal college teacher must be an investigator, but until we 
have passed the present stage of rapid growth in our State colleges, 
nothing comparable to the proper proportions in the division of his 
energies between these fields is practicable. The duties of public 
adviser or extension servite in plant pathology may not be wholly 
incompatible with college teaching or station research, although at 
times seriously distracting. I am, however, convinced that in such 
matters the professional plant pathologist may in general wisely 
delegate the responsibility to act as spokesman to his associates in 
horticulture and agronomy. The nature of a disease and its mode 
of control once settled, the application of control measures becomes 
simply one factor in the complex of cultural operations for the execu- 
tion of which the above departments become responsible. 
Plant disease surveys, inspection and quarantine service belong 
in still another class and deserve the attention of experts in plant 
pathology. But back of all these must stand the investigator, with 
time and faculties kept free for his fundamental work; for research 
‘is the most exacting of all taskmasters. While no one realizes more 
1See Stuart, Wm., Disease resistance of potatoes. Vt. Agr. Exp. Sta. Bul. 122. 1906. 
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