108 THE PLANT WORLD. 



work in the prevention and treatment of diseases. While some 

 of this work can be begun in the hiboratory and the greenhouse, 

 it can only be carried to successful completion under held condi- 

 tions, consequently the pathologist must either be giveli oppor- 

 tunity to grow plants under field conditions, or must be inti- 

 mately associated witli those who are engaged in that kind of 

 work. As much of the scientific work in the prevention and 

 treatment of diseases is done in connection with our Agricultural 

 Experiment Stations, I must urge the importance of the closest 

 co-operation with the departments of agronomy and horticulture. 

 Due to the fact that in some of our stations the horticidturists 

 have been obliged to serve the double role of horticulturist and 

 botanist, we find some of our horticulturists claiming all spray- 

 ing work or any treatment of horticultural crops for disease, al- 

 most as one of their sacred rights, while the pathologist if he 

 pleased them would remain in his laboratory and diagnose the 

 diseases that were called t(t Ids attention. Wouhl it be anv more 

 absurd for the animal husbandman to insist that the treatinent 

 of blackleg, or mange, was a province of his department, and 

 that the veterinarian should simply l)e his encyclopaedia of in- 

 formation? Experimental and demonstration work in the field 

 in the treatment of diseases, either animal or plant, can not log- 

 ically be divorced from the accurate laboratory study without 

 causing the work to suffer, consequently it is to be hoped that the 

 co-operation suggested can be fully realized. 



Much has been accomplished in the work of prevention and 

 treatment of diseases by co-operative work with progressive 

 farmers, fruit-growers, truck-gardeners, etc., in different parts 

 of the country, and this must continue to be a fruitful field for 

 work. The co-operative work with farmers must be in many 

 oases only in the nature of demonstrations of the effectiveness of 

 well-known treatments, while frequently intelligent and pro- 

 gressive farmers will interest themselves in the experimental 

 side of the treatment and prevention of plant diseases. 



Much (d" the work on the etiology of diseases must be car- 

 ried on in the field, and access to plants grown under natural 



