If 





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Fig. 92. Plasmodiophora brassicae. i, a young turnip 

 showing the early stage of the disease ; 2, a cabbage plant 

 with clubbed root ; 3, two diseased cells from the root of 

 a cabbage, one contains plasmodium, the other is crowded 

 with the minute spores of the parasite ; 4, three myxa- 

 moebae or motile bodies produced by the spores on 

 germination, very highly mag. ?. I 



