Inter-Relationships of Protista and Primitive Fungi 303 
F 10 . 6. Chytridiales. A. Olpidium salicornia : 1, part of section of host 
showing on the right the remains of an infection-tube and (above) a young 
sporangium, on the left an empty sporangium with exit-tube; 2, young 
parasite with one nucleus; 3, above are two amoebae fusing, below is an 
amoeba with four nuclei; 4, on the left a cyst, on the right a parasite under¬ 
going nuclear division. B. Ectrogella bacillariacearutn : 1, young zoosporangia 
in Synedra ; 2, empty sporangium with several exit tubes. C. Pseudolpidmm 
sp. : 1, empty zoosporangia in a Saprolegnia hypha ; 2, zoospore ; 3, spiny-coated 
cyst with exit-tube. D. Pleotracheliis fulgens : zoosporangium with several 
exit-tubes, zoospores escaping. E. Olpidiopsis vexans: 1, three empty spor¬ 
angia and two mature oospores in a Saprolegnia hypha ; 2, fusion of antheridium 
and oogonium (nuclei of antheridium in division, those of oogonium in the 
resting condition); 3, sexual organs, showing passage of male nuclei into 
