SECTION 2. 



HISTORICAL SURVEY. 



In any branch of knowledge so young as phytopathology, any history 

 of the science can scarcely be presupposed. And in fact the date after which 

 the teaching of plant disease was set up as a special branch is so recent that we 

 are still able to survey completely the course of its development. 



If, however, the form of investigation is still new, the material, viz., 

 leports on plant diseases, is very old, extending far back in history. We can 

 not go astray in assuming that there have been diseases since the existence of 

 the plants began and that observations on these began with their cultivation. 

 For we constantly see what heavy injuries are produced by atmospheric ex- 

 tremes, and indeed not only by those disturbances which instantly kill the 

 plant, but rather by such as weaken the individual in structure and form, 

 and slowly lead it toward a premature death, — i. e. make it sick. The action 

 of injurious atmospheric conditions must have existed always and have 

 made themselves evident in different forms. 



One of the oldest names which we find for certain forms of sickness, 

 is "blight." On this account we will attempt to trace the growth of our 

 branch of knowledge by following the observations of the diseases which 

 this name connates. 



As the later reports show, at first all those phenomena were character- 

 ized as "blight," which appeared to the eye to have the color of burned or 

 charred matter, that is, black. Accordingly "blight" comprised on the one 

 hand the groups of tree diseases, in which the dead bark assumed a black- 

 ened appearance, on the other hand also the injuries to grain, the causes of 

 which we trace back to smut and rust fungi. 



If we look first in the Bible for mention of diseases and especially of 

 "blight," we find, for example, the following: — ^"If there be in the 

 land famine; if there be pestilence, blasting, mildew, locust, or if there be 

 caterpillar; if their enemy besiege them in the land . . . ." Again: — 

 -"The Lord shall smite thee with consumption and with a fever, and 



1 First Book of Kings, Chapter VIII, 37. Second Booli of Clironicles, Chapter 

 VI, 28. 



2 Deuteronomy, Chapter XXVIII, 22 



