no 
L. R. JONES 
improvement through breeding is recent. The relative success of the 
German and Scotch breeders in securing disease resisting potatoes is 
fully recognized. 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 
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 sug- 
gestive 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 difliculty 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 today upon the American phytopathologist is almost 
equally urgent for four types of service: (i) college teaching, (2) ex- 
tension 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 service 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 
" See Stuart, Wm. Disease resistance of potatoes. Vt. Agr. Exp. Sta. Bui. 122. 
1906. 
