Communications. 



271 



POTATO BLIGHT AND ROT. 



By Tno>fA9 Taylor, M. D., and Microscopist Department of Agriculture. 



The potato disease was first observed in Germany, near Liege, 

 in 1842 ; in Canada in 1844, and in England in 1845. In the 

 following year it prevailed very extensively over almost all parts 

 of Europe. The summer was unusually cloudy and moist, a cir- 

 cumstance which doubtless had great effect in fostering the dis- 

 ease. It has been estimated that the damage sustained by Great 

 Britain and Ireland in the year 1845 was not less than £ 21,000,000, 

 and in 1846 probably twice that amount. The London Times in 

 1872 stated that the loss sustained by Great Britain during that 

 year, in consequence of this disease, amounted to from £20.000,000 

 to £30,000,000. 



Fio. 1. Sectiok 8Ho^\-I^•G Stakcu Cells. Vasculab Bundles. Right side uigult 



MAGNIFIED. 



For forty years past the potato-rot has been attributed wholly 

 to a parasitic fungus known as Boirytis ivfestans. It has been 

 observed that this fungus attacks the leaves at first, causing 

 brown blotches. The disease is next transmitted to the stalks 

 and tubers, and in a few days the leave?, stalks and tubers become 

 a fermenting mass. 



By the aid of the microscope, the spores of the fungus Botrytis 

 infestans may be easily observed, although very minute. With a 



