276 PLANT DISEASES 



tioned briefly merely to call attention to the diversity 

 of life stories in the smuts. Ordinary seed treatment 

 as described above will not prevent the loose smut of 

 either wheat or barley. The reason for this is as follows : 

 These smuts are early smuts ; that is, the smut mass is 

 produced early in the summer. The spores are blown 

 about by the wind, and some of them are blown into 

 the flowers of healthy wheat plants, where they im- 

 mediately begin to grow. The threads then get into 

 the seed before the latter ripens, so that at harvest time, 

 in the case of loose smut of wheat and barley, we have 

 the fungous threads already inside of the seed buried 

 to some depth in the germ. The difference between 

 this smut and the stinking smut of wheat and covered 

 smut of barley, where the spores are on the outside of 

 the seed, can be seen. It should be clear that where 

 the fungous disease is already inside of the seed, the 

 ordinary washing or poisoning of the outside of the 

 grain will not be effective, and this has proved to 

 be the case. The ordinary seed treatment is there- 

 fore useless. The only effective method known at 

 present is to soak the grain for some hours and then 

 to treat it severely with hot water, which apparently 

 kills the fungi inside of the grain and does not kill all 

 the grain, although some of it is not strong enough to 

 survive. 



It will be seen from this description of the smuts that 

 if a farmer has smut in his barley, in order to handle 

 it intelligently he must know whether it is covered 

 smut or loose smut, the treatments in the two cases 

 being different, because the life stories are different. 



The Blight of Potatoes Spraying. Potato blight 

 is an exceedingly serious disease, especially in wet 



