276 ANNALS OP THE MISSOURI BOTANICAL GARDEN 



[Vol. 2 



University of Munich, in which von Tubeuf has been and is 

 still teaching the subject. In Austria, Hecke has been giving 



lectures for some years. In the United States there has been 

 much progress in this line, due, no doubt, to the fact that 

 plant diseases are of greater importance here than in any 

 other country. As the number of chairs in phytopathology 

 in our institutions of learning increases, however, the rela- 

 tion between scientific botany and phytopathology will be- 

 come more and more intimate. 



Among the factors which favor unusual ravages by vegeta- 

 ble and animal parasites, I wish to mention the rapid develop- 

 ment of agriculture by way of growing the same varieties or 

 races over vast areas, the great fertility of the previously 

 uncultivated soils, which often induced people to crop the soil 

 and neglect rotation, and lastly the favorable climatic condi- 

 tions, which not only favor the cultural plants but also their 

 parasites. 



One of the oldest problems of phytopathology is the smut- 

 problem. Since ancient times smuts have been among the 

 most important plagues of our cereals, and long before we 

 knew the cause of these diseases people tried to control them. 

 But rational measures of control could not be developed 

 before the cause of the disease was known. Julius Kiilm 

 succeeded in clearing up the life-history of the stinking 

 smut. This was the first distinct step in advance, but here, 

 unfortunately, progress ceased for some time, principally 

 because of the lack of knowledge concerning the taxonomy 

 of the smut-fungi. All loose smuts of oats, wheat, barley, and 

 the close smuts of oats and barley were united under the 

 single species Ustilago carbo. This prevented the investiga- 

 tions of the biology of the smuts, and it was not until the 

 fact was demonstrated that various species of smuts were 

 concerned that the way was opened for the proper investiga- 

 tion of the biology and subsequently also of the control of 

 the parasite. 



The development of our knowledge of the smuts was due 

 to the biological facts demonstrated by Brefeld and Hecke. 

 They discovered that infection takes place through the 



