22 PROTECTION OF PLANTS — 1922-23 



may not give special emphasis to the applications and economics of the subject. 

 The practicioner will be the man of the field, the worker who has to do primarily 

 with the applications of the subject and who will also be an immediate advisor 

 to the agricultural public. There will be no definite or fixed lines between these 

 groups of workers, but the}' will naturally classify themselves to a greater or 

 less degree. Each Avill give to and receive from the others, and the result will 

 be the general advancement of the science of plant pathology and of agriculture. 



The training of these workers will varj' in degree rather than in kind. The 

 research men must of necessity be thoroughly grounded in the mother science — 

 botany, and in the various phases of other sciences, such as chemistry, physio- 

 logy and zoology, which contribute to their proficiency. The specialists or 

 experts must have the same groundwork with such other training as will make 

 for success in their chosen fields. The practicioners may not be so thoroughly 

 trained in the related sciences referred to, but they must have the groundwork 

 and such training in horticulture, agronomy and allied subjects as will contri- 

 bute to the success of coiitrol measures and crop production. 



A knowledge of the taxonomy of both the host plant and the parasite must 

 be the very backbone of the profession. We must know, we must understand 

 so far as possible both the diseased plant and the cause of its troubles. Taxo- 

 nomy may be prosaic and uninteresting to manj-, but it is necessary for the 

 advancement of the science. Many of our present records are of little or no 

 value because of incorrect determinations and many of the conflicting statements 

 are due to the same cause. The solving of the taxonomic relationships of many 

 groups, especially the ascomycetes and the imperfecti is extremely difficult, 

 but it is necessary in order to solve man}' of our economic problems in plant pa- 

 thology. This work will be materially aided by the introduction of modern 

 culture methods. 



A knowledge of the morphology and anatomj- of both host and parasite is 

 of as great importance to the plant pathologist as a knowledge of human anato- 

 my to the surgeon. The workof Quanjer and Artschwager on the structure of 

 the potato plant when infected with leaf-roll are good illustrations of this point. 

 The plant pathologist of the future must know the morphology and anatomy 

 of the host plant in both health and disease and this will lead to a development 

 of that much neglected branch, — patho-anatomy. Furthermore, he must be 

 familiar with the life history of both the host and the parasite in order that the 

 treatment may be applied at the most critical period in the history of the latter, 

 and that it may not be injurious to the former. 



