iv.] NEW DISEASE OF POTATOES. 29 



these nodules are destined to germinate and produce the 

 Peziza disease the following year. 



The remedy for this state of disease is obvious. No 

 infected stems should be allowed to rot in the fields, but 

 all should be carefully gathered together and burnt. If 

 the stems are allowed to rot on the ground the disease is 

 almost certain to recur ; but if they are burnt not only 

 will the Sclerotia of the Peziza be destroyed, but the 

 spawn, germs, eggs, and spores belonging to numerous 

 other parasites, perhaps equally bad with the Peziza 

 itself, will be destroyed at the same time. If, on an 

 examination of the potato stems, it is found that many of 

 the Sclerotia have dropped from them, the top surface of 

 the ground should if possible be raked and burnt. 

 Nothing is more common than to find hibernating repro- 

 ductive bodies falling readily to the ground. This is 

 clearly a natural provision for their preservation. 



