126 PROTISTS AND DISEASE 



then formed. They differ from the trophonuclei by having 

 no nucleoli. Two successive karyokineses then take place, 

 and the plasmodium subdivides into spores, 4. 



The absence of a Capillitium from the life of Plasmo- 

 diophora distinguishes it from the Mycetozoa, but such 

 distinctions are not radical : such features might be 

 suppressed in parasitic adaptation. 



The absence of a sporangium allows the spores, which 



WjF^ 



vk :?: /M 



ff 



FIG. 34. PLASMODIOPHORA, NUCLEAR PROCESSES. 1, Amoeboid stage 

 with trophonuclei ; 2, chromidial or akaryote stage ; 3, karyokinesis 

 in new nuclei ; 4 and 5, spore-formation. From Part III. After 

 v. Prowazek. 



are in great numbers, distending the otherwise empty cell- 

 walls of the host, to collect into roundish masses moulded 

 to the space in which they are contained. 



The individual spores have a thin doubly- contoured 

 capsule. In August, 1918, a friend gave me some badly 

 diseased cabbage-roots from his garden at Chesham Bois, 

 Bucks. a rather heavy, chalky, and flinty soil. I made 

 many observations on scrapings from a slice of root kept 

 partly in and partly out of water, but I did not succeed in 



