122 Early Work in North America 



The plant diseases caused by the Peronosporaceae were among 

 the most serious known at this time. About forty "members of 

 the small order "^°® were known to occur in the United States; 

 and, among the more important of the maladies, were the potato 

 rot and the grape-vine mildew caused by Peronospora viticola. 

 In New York State, during 1884, one- third of the potato crop had 

 been destroyed by the rot, and no positive remedy for the disease 

 was established. The grape-vine mildew had done "much injury 

 to the grape-vine in this country, and more recently to the vines 

 of Europe." ^°^ Since the 1870's"° Americans had been watching 

 with interest the efforts of the French nation to conquer the grape 

 phylloxera, and C. V. Riley, at the recent pomological society 

 meeting,"^ had told his audience that grape mildew due to 

 Peronospora was novv' regarded as more serious in France than 

 the grape phylloxera. It was hoped that the phylloxera would be 

 combatted by grafting certain American vine stocks resistant to the 

 pathogene onto the more susceptible European vines. An " im- 

 mense traffic" "" in American cuttmgs had resulted. But with the 

 shipments the Peronospora, until within the past few years un- 

 known to the grape-growers of France, had been introduced from 

 this country. ^^^ 



The hope for solutions of the Peronospora diseases of the grape 

 and the potato lay in studying out the life-histories of the fungi 

 and finding some point in their development-cycles when attack 

 by a fungicide or other remedy would prove effective. The Uni- 

 versity of Michigan had no college or department of agriculture. 

 Professor Spalding's idea of botanical research, however, was 

 broad and included investigations in plant physiology, plant 

 pathology, and mycology. By no later than October 9, 1885, 

 Erwin Smith, in the university botanical laboratory, was sowing 

 conidia of Peronospora viticola in water on a slide; and, after an 

 hour had gone by, was finding "what seemed to be, and un- 

 doubtedly were, swarm spores swimming in the water. At first 

 [he] saw only a few but in course of [the] next half hour saw 



'"* F. L. Scribner, Rep't of the Comm'er of Agric. of U. S. for 1885: 83. 



"■"" Idetn, 82-84. 



^^'' Rep'ts of the Comm'er of Agric. for 1873: 160, 289, 389; for 1876: 81. 



^^^ Proc. 20th Sess. Amer. Pom. Soc, for 1885: 52. 



"' C. V. Rilev, Rep't of the Com7n'er of Agric. for 1884: 406. See also p. 288. 



^^^ Proc. 20th Sess. Amer. Pomol. Soc. for 1885: 52. 



