THE SCIENCE OF PLANT PATHOLOGY. 401 



lordelaise, Bordelaiser Brulie, or Bordeaux mixture, a proved fungi- 

 cide of great efficiency ; one that has not yet been surpassed. 



In the new world the extension of the potato belt westward con- 

 nected the eastern potato belt with the region of the native food plant 

 of the familiar potato bug. Finding the potato plant a more abundant 

 and wholesome food than the wild solonaceous plants that it had form- 

 erly fed upon, the potato bug began its eastern migration. In 1859 it 

 was found east of Omaha City, in 1868 it had reached Illinois, in 

 3870 Ontario, in 1872 New York and in 1874 it was upon the Atlantic 

 seaboard. The potato bug ate ravenously and man was stimulated 

 to new activity in the search for more effective means to overcome 

 insect pests. The use of Paris green and London purple followed as 

 a direct result of this stimulus. 



The development of efficient fungicides and insecticides in Europe 

 and America led naturally to the perfection of the machines used in 

 applying these mixtures, and not the least important part played in 

 the development of a practical plant pathology is concerned with the 

 evolution of spraying machines. The first sprayer consisted of a 

 bunch of switches. This was dipped into the spraying mixture which 

 was distributed over the foliage by vigorous shaking. It gave place 

 to an improved spraying broom or brush with hollow handle, the 

 liquid flowing from a reservoir to the brush, from which it was ap- 

 plied to the leaves. Sprayers and pumps followed in turn. Then 

 came the improvement of the nozzle. 



We may recognize two periods in the development of plant pathol- 

 ogy: the first or embryonic period extending from prehistoric times 

 to the beginning of the truly scientific investigations in the middle of 

 the eighteenth century, and contributing chiefly observations, collections, 

 descriptions; the second or formative period, during which the founda- 

 tions of the science were laid, the chief factors of it determined, and 

 the chief lines of future progress marked out. 



It is in no way my purpose to call attention to the part the Caro- 

 linas have played in botany as a science, yet I can not refrain in passing 

 from mentioning that prominent place in the history of American 

 mycology is assured to de Schweinitz, a minister of Salem, N. C., 

 who in 1818 published the first important paper on American fungi; 

 to M. A. Curtis, a tutor in Wilmington, N. C, who in 1830, with 

 Berkeley in England, described many fungi of the Carolinas; to 

 Eavenal, of South Carolina, the first to publish exsiccati of American 

 fungi, and to Louis Bosc, of South Carolina, who published a de- 

 scriptive list in 1811. 



The embryonic and formative period prepared the way for the 

 third period, beginning about 1885, which may be called the period 

 of growth. It is marked by the development and perfection of the 



vol. i/xvn. — 26. 



