Sclerotia 



almost wholly to the parts of the plant below ground, 

 such, for example, as wart disease of potatoes, 

 club-root of cabbages, and the like, and may become 

 evident only when the plant is lifted. On the other 

 hand, destruction or damage to the absorbing roots 

 may occur and wilting of foliage foUow. The spores 

 of the fungi concerned are present in the soil about 

 infected plants, and are carried from place to place 

 not only on or in infected plants, but with the soil 

 itself. Little imagination is required to picture the 

 trouble likely to arise from conveying such soil on 

 plants during transplanting, on tools, boots, carts, 

 and the Uke, from infected to clean situations ; the 

 wind-borne dust may carry the spores too. 



Certain fungi form masses of mycehum which 

 rest through ungenial seasons. Pieces as large as 

 peas or larger, generally black, occur inside the stem 

 of Dahhas or potatoes when attacked by the "Sclero- 

 tium disease." They are black outside and soHd, 

 rather Uke wax to cut, and will withstand drjdng 

 and other conditions unsuitable for growth. Such 

 masses are called sclerotia, and the term " Sclerotium 

 disease " is derived from their name. " Fire " in 

 tulips is due to one of them. Curious sclerotia are 

 formed by the fungus which attacks the roots of 

 anemones and sends up brown cups in spring where 

 one looked for a brilliant display of blossom. The 

 whole root is permeated by the fungus, and the 

 sclerotium assumes the form of the root which the 



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