786 



AQUATIC PHYCOMYCETES 



Fig. 59. Plasmodiophoraceae 



A-B. Sorodiscus karlingii Cook in Chara: A, two of a whorl of leaves 

 showing strongly hypertrophied corticating cells on each leaf; B, sorus of 

 resting spores composed of approximately two hundred cells. C-D. Sorodiscus 

 cokeri Goldie-Smith in Pythium: C, two convex cystosori; D, discharging 

 sorus of zoosporangia, the zoospores passing from inner to outer sporangia 

 and thence through pores to the outside, the zoospores undergoing amoeboid 

 change of shape before swimming away; the zoospore body bears a contrac- 

 tile vacuole, scattered droplets, and a long refractive body. E-H. Woronina 

 pythii Goldie-Smith in Pythium proliferum: E, young zoosporangial sorus; F, 

 zoosporangial sorus, one sporangium of which has a swollen exit tube; G, 

 mature zoosporangial sorus with peripheral refractive residual host material; 

 H, mature cystosorus. 



(A-B, Karling, 1928c; C-D, Goldie-Smith, 1951 ; E-H, Goldie-Smith, 1956a.) 



