220 PLANT DISEASES 



copious mycelium and numerous conidia. This mode of 

 reproduction is capable of developing and increasing for 

 some time under favourable conditions, as in a manure- 

 heap ; such infected manure, if used on land where wheat 

 is to be sown, commences the disease. 



PREVENTIVE MEANS. The hot-water method, taking 

 everything into consideration, is best. Corrosive sublimate 

 (mercuric chloride) is also efficacious in preventing the 

 disease. The grain should be sprinkled with a solution of 

 one pound of corrosive sublimate to fifty gallons of water ; 

 the wheat should be raked or shovelled about till the surface 

 of every grain is wet all over. Metal must not come in 

 contact with the solution, which is poisonous, and should 

 be used with care. 



Bolley and Close, American experimenters, have dis- 

 covered that formalin (a forty per cent, of formaldehyde), 

 used at the rate of one pound to fifty to sixty gallons of 

 water, is effective against stinking smut of wheat and 

 loose smut of oats. The seed should be soaked two 

 hours. 



Wheat sown in the spring is invariably more ' smutted ' 

 than when sown in the autumn. 



Brefeld, Unters. aus dem Gesammt. der MykoL, v. Heft, 

 p. 146, Taf. xii.-xiii., figs. 25-52 (1883). 



Tilletia levis, Kiihn = Tilletia foetens, Arthur. De- 

 veloped in the grain of wheat, like T. tritici, which it 

 resembles in appearance and smell, but differs in the 

 perfectly smooth spores. This species appears to be most 

 abundant of the two in the United States, whereas it is 

 rare in Europe. Treatment same as for Tilletia tritici. 



