[93] 



Smut of Mbcat, ®at5, an^ Badci? 



Ustilaco carbo. Tul. 



EVERY person, even the most unobservant, who has walked 

 through a field of wheat, oats, or barley, must have noticed 

 smutted ears. Instead of the healthy spike or panicle of 

 grain being presented, a sooty, ragged mass of black dust and 

 scales is seen surmounting the fruiting stems of the corn. In 

 some places the disease is called " chimney-sweeper," in others 

 " black ball," " dust-brand," or " smut." In certain districts it is 

 erroneously termed " bunt," which is a totally different disease of 

 corn. The black powder is produced in such profusion that it is 

 impossible to gather a few diseased ears without the hands being 

 soiled as if with soot. We have heard smutted ears called " the 

 male flowers of corn " by some country folk, the erroneous idea 

 being that these diseased ears are the male, or the black pollen- 

 bearing plant. Some districts are more liable to Smut than others, 

 although none are free. The disease is sometimes extremely 

 destructive, especially in oats. In some instances nearly the 

 whole crop becomes smutted, and in bad cases from one-sixth to 

 one-third of the crop is destroyed. When smutted wheat is 

 ground with sound grain, it not only seriously discolours the flour, 

 but it injures it as food. Straw infected with the black powder or 

 spores of the Smut fungus is disliked by cattle, and it is an offen- 

 sive adjunct to chaff when given in food to the animals of the farm. 



The Smut disease of corn is caused by the presence of a 

 fungus which exists within the tissues of the plant, grows with the 

 growing stem, and at last bursts from the inside of the plant out- 

 wards at about the time when the corn is reaching maturity. The 

 name of the fungus is Ustilago carbo. The name is derived from 

 Ustio., which means a burning, and carbo., which means charcoal — 

 the compound name of the fungus having direct reference to the 

 burnt and sooty appearance of the parasite. 



We will now make a close examination of the extremely 

 curious fungus which causes Smut, and show how it invades the 



* We are indebted to Messrs. Webb and Sons, of Wordsley, for this 

 paper and for the excellent engravings with which it is illustrated. 



