CHAPTER XVII. 



CLUB-ROOT OF TURNIPS, CABBAGES, MANGELS, AND 

 ALLIED PLANTS. 



Plasmodiophora Brassicce, Wor. 



THE disease of turnips, cabbages, and allied plants, known 

 in some districts by the popular name of club-root, is 

 recognised in other places as anbury and finger and toe. 

 On the continent the disease is popularly known as hernia 

 or rupture. 



Until the last six or seven years no one knew the cause 

 of club-root, but in 1876, after three years' constant atten- 

 tion, M. Woronin, a Russian botanist, as completely 

 explained the nature of club-root in turnip and cabbages, 

 as the Rev. M. J. Berkeley expounded the nature of the 

 murrain of potatoes in 1846. 



The observations made by M. "Woronin, which have 

 several times been confirmed by others as well as ourselves, 

 seem to place the fact beyond all doubt that clubbing is 

 caused by a fungus named, by M. Woronin, Plasmodiophora 

 Brassicce. Plasmodiophora means a bearer or carrier of a 

 plasmodium, and a plasmodimn is an Amoeba-like mass of 

 protoplasm or vital formative material of changeable form ; 

 Brassicce, of course, means that the fungus is peculiar to 

 the turnip and cabbage class. The family to which the 

 fungus belongs is a remarkable one, and is known as the 

 Myxomycetes or family of slime-fungi. These fungi have 

 appeared so animal -like to some observers that, by a 

 misinterpretation of analogies, an attempt has been made 

 to transfer them to the Protozoic division of the animal 

 kingdom. With the same idea in view they have been 



