22 DISEASES OF FIELD & GARDEN CROPS. [CH. 



in dead potato stems in the spring, but not on living 

 potato plants in the summer. 



Great efforts were made both by ourselves and numer- 

 ous friends to make the new potato Sclerotia germinate, 

 but in every instance that year without result. Many 

 enquiries were made of potato growers, but the Sclerotia 

 appeared to be lost again to this country, and nothing more 

 was heard of them till a paragraph appeared in Nature 

 for 19th July 1883. This described, from Natureen, a so- 

 called hitherto unknown form of the potato disease, which 

 had been making slow but steady progress near Stavanger 

 during the previous ten or twelve years, and was then, so 

 said the report, showing increased energy. The potato 

 stalks were reported to be the first parts affected, and 

 here Herr Anda had discovered small white fungoid 

 growths, which, after attaining the size of a small bean, 

 finally assumed a black colour. It appears that the 

 fungus at Stavanger, like the same growth on the west of 

 Ireland, rapidly increased at the expense of the supporting 

 plant, first reducing the interior of the potato stem to a 

 pulpy condition, and then shrivelling and hollowing it 

 out until nothing was left but the mere outer shell. 

 About the end of July or the beginning of August the 

 destruction caused by the fungus is seen at its worst, 

 and at this period whole fields of potato plants are often 

 reduced to the condition of withered straw. 



Now this disease at Stavanger, which was more or less 

 lost sight of in Britain for three years, was clearly identi- 

 cal with the one reported on by us ; it agreed in every 

 way, and we at once wrote a note to Nature expressing 

 our regret that although the germinating Sclerotia had 

 apparently been seen by Herr Anda, yet the perfect plant 

 had not been identified ; so that, so far as Herr Anda's 

 report went, we were as much in the dark as before as 

 to the fungus which had caused the disease. A few days 

 after our letter was published, our friend Mr. A. Stephen 

 Wilson, of North Kinmundy, Summerhill, by Aberdeen 



