Report of the Botanist. xxi 



In the vicinity of Kochester a new stem disease of the snap- 

 dragon has been found. Affected plants or brandies first wilt, and 

 then soon die. The fungus attacks the vascular system particularly. 

 The organism causing this disease has been isolated and studied in 

 the laboratory, and the disease repeatedly produced by the artificial 

 infection of healthy pknts with pure cultures. Apparently, the 

 fungus may only gain entrance where the stem is injured, or where 

 it remains constantly moist ; and soil inoculations have always 

 given negative results. 



Less important diseases of plums and apricots, pseonies, asters, 

 and some other ornamental plants have received some attention. 



In addition, during the summer of 1900 calls were received to 

 make inspections of beet fields badly affected with leaf spot and of 

 celerv fields troubled with the late blic^ht. 



A blight of maple trees caused by the hot winds and by other 

 injurious conditions was so prevalent in August, 1900, and demanded 

 so much correspondence, that a circular letter explaining the disease 

 was issued. Peach leaf curl was also verv abundant and injurious 

 during the past sprino; and necessitated considerable correspondence. 



Some studies made by students taking work with me have yielded 

 results which will have important bearing upon certain questions of 

 economic interest in plant pathology and physiology. The results 

 of this work have not been published, but it may be said that Dr. 

 J. F. Clark has studied in detail the toxic action of many of the 

 copper compounds upon the fungi, with special refei'ence to 

 Bordeaux mixture ; and light has been thrown upon tlie method of 

 action of this important fungicide. Dr. Margaret C. Ferguson has 

 studied the physiology of the germination of mushroom spores. Her 

 successful results with the germination of the spores of Agaricus 

 campestris, the common mushroom, lead us to believe that soon we 

 will be able to grow in pure culture, the mycelium, or spawn of this 

 mushroom in a practical way. Previously the only successful 

 studies in the germination of such spores have been made by certain 

 French investigators, particularly at the Pasteur Institute, Paris, 

 where the methods employed, unfortunately, are strictly secret. 



Very respectfully submitted, 



B. M. DUGGAR, 



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