Dec. 18«5.] 



INJUEIOUS INSECTS AND FUNGI. 



S25 



enough wheat to furnish seed for the following year, and this 

 should be done when any considerable per cent, of the crop is 

 affected." In treating wheat for loose smut, Messrs. Kellerman 

 and Swingle advise that the grain should be soaked for four hours 

 in cold water, then put away about four hours more in wet sacks, 

 and finally put in hot water, but only for five minutes, at a 

 temperature of J 32° Fahr. But they add, "in planting, one half 

 more seed must be used per acre to compensate for the seed 

 killed by the treatment." 



Bunt (Tilletia tritici, Bjerkander ; Tilletia Caries, Tulasne) 



A. Wheat grain attacked by Tilletia, enlarged 4 diameters. 



B. Section of grain, showing farina replaced by spores of fungus. 



C. Cross section of infected grain. 



D. Spores of Tilletia, two germinating and producing rods, one at the right 



producing a conidium, enlarged 400 diameters. 



E. Conidium germinating, enlarged 400 diameters. 



" Bunt," or " stinking smut," is more injurious to the wheat 

 crop than loose smut, Ustilago tritici, as the grains infected by 

 it are formed and conveyed full of its spores into the ricks or 

 barns, and when the corn is threshed many of them go into the 

 heap, or in the sacks, with the sound grain, whereas loose smut 

 destroys the grain in its embryonic state. Before wheat plants 

 are fit to cut it is not always easy to ascertain whether they 

 are bunted unless the plants and ears are examined with some 

 attention and the discoloured grains exposed to view. In the 

 case of smut the ears are completely disintegrated, and nothing 

 is left but the blackened stems. Sometimes the ears that have 

 bunted grains within them are greener than those nob infected^ 

 and appear to be more luxuriant. As a rule, this difference is 

 shown when the plants are seven or eight inches high, and they 

 do not generally grow so tall as those that are not bunted. An 

 observer would also notice that the infected ears are pale in colour, 

 and have a bleached appearance, in contrast with the brown 

 hue of red, and the golden tinge of white, wheats. Infected 

 grains are distorted and swollen, and are shorter and smaller than 



