334 



PLANT DISEASES 



and finally scattered over the entire surface. At a later 

 stage these blotches are studded with minute black spots 

 or stromata, which on being magnified are seen to be 

 bordered with a fringe of black, pointed hairs. The con- 

 idia are long, narrowly cylindrical, and colourless. No 

 preventive measures appear to have been tried, but 

 probably the spread of the disease could be checked by 

 cautious spraying with a fungicide, very dilute to com- 

 mence with, until its action on the foliage is observed. 



Oudemans, Comp. Rend. Acad. Roy. Sci. Pays-Bas, 1896, 

 p. 226. 



MYXOGASTRES 



' FlNGER-AND-TOE ' 



(Plasmodiophora brassicae, Woronin.) 



This destructive disease, known in different parts as 

 1 finger -and -toe,' 'club-root,' and 'anbury,' attacks the 

 various kinds of cabbage, turnips, radishes, wallflowers, 

 in fact most cultivated plants, as well as weeds belonging 

 to the Order Crudferae. 



The root is the part most frequently attacked, the 

 presence of the parasite being indicated by the formation 

 of numerous nodules, or wartlike outgrowths, or the entire 

 root becomes swollen and clubbed, eventually rotting and 

 emitting a very disagreeable smell. 



The disease also exists in the leaves, at least in the case 

 of cabbages, but no distortion occurs, as in the root. 



Berkeley appears to have been the first to investigate 

 the disease; and, although he failed to determine the 

 true cause, was convinced, as the result of microscopic 



