PLASMODIOPHORACEAE 



125 



trophic, and have been compared to the " bird's-eye " 

 bodies of cancer, and with which, I believe, they may be 

 homologous. In this intracellular stage the parasites appear 

 to subdivide without any nuclear division. They occupy 



FIG. 33. PLASMODIOPHORA BRASSICAE. 1, Rootlets of infected cabbage ; 

 a, surface view, after Woronin ; b, section, after L. Pfeiffer ; 2, section ; 

 a, 4 multi-nucleate parasites in a cell ; 6, plasmodium, the nuclei 

 subdividing ; c, and d, spore-formation ; 3, stages in the hatching of 

 a zoospore. x 250 diams. From Part I., modified from Doflein 

 after Woronin. 



an increasing amount of the space in the cell, and are said 

 to fuse together into a plasmodium, 2, a and b. 



The nuclear processes in Plasmodiophora are shown in 

 Fig. 34. 



The trophonuclei lose their chromatin, which passes 

 into the cytoplasm, 1 and 2. The reproductive nuclei are 



