Fungous Disfasi-s of Plants, Pi;a(h ^'i i.lows 137 



'■he growth of definite scientific knowledge" wliich began soon to 

 displace "vague theories and uncertain experiments." 



By 1886 the Department of Agriculture's herbarium was "one 

 of the largest and most valuable in the country, and contain [cd] 

 a representation of nearly" 12,000 native phaenogamous plants, 

 as well as large numbers from Mexico, South America, and other 

 countries.'' Smith had been reading about American and English 

 collections of fungi for many years. The Commissioner's report 

 for 1886 mentioned no such collection at the Department, but he 

 did announce that experimental investigations were under way to 

 study fungous diseases of plants. More than 200 species of fungi 

 were believed to attack the grape vine. Annual losses from dis- 

 eases of corn and wheat were estimated at approximately $200,- 

 000,000. Potato rot in wet seasons had been so destructive that 

 the loss in 1885 was placed at from ten to forty per cent of the 

 entire crop. Very serious crop losses were reported also for cotton, 

 orange, apple, peach, pear, plum, quince, and other industries.'' 



Scribner believed that the " most important work " of his section 

 that year had been the issuance of his and Smith's Bulletin 2? 

 His account of "Fungus Diseases of the Grape- Vine," occupying 

 practically one-half and the title of the bulletin, was to have such 

 a demand for copies that in 1890 he would publish a book ^ on the 

 subject, and in 1886 included in his report abstracts of the leading 

 topics: the downy and powdery mildews, black rot, anthracnose, 

 etc. So v\idespread and abundant were the inquiries that from 

 them in part the workers were enabled to map the distribution 

 and severity of the diseases. Professors S. M. Tracy had written 

 the Department concerning celery-leaf blight. This subject, to- 

 gether with material on orange-leaf scab and the potato-rot, a 

 summary by Arthur of his and Burrill's study of pear blight, and a 

 discussion by Trelease of an orchard grass spot disease, comprised 

 the main parts of the section's report for that year.^ 



In 1885 Scribner, while Vasey's assistant, had prepared for the 

 annual report of the Division of Botany a treatise of some twelve 



'Report of the Botanist, Rep't of Comm'er of Art'ic. for 1886: 70. 

 ' N. J. Colman, Comm'er, Rep't of Comm'er of Agric. for 1886: 28. 

 "U. S. Dep't Agric, Bot. Div. Bull. 2: 1-136, 1886. 



' Fungus diseases of the grape and other plants and their treatment, J. T. Lovett 

 Co., Little Silver, N. J., 136 pp. 

 "Op. cit., 96-131. 



