60 



PBOTISTS AND DISEASE 



2. Cladochytriaceae (Gr. klados = branched). This group 

 is described by de Bary as having a delicate, rhizoid-like, 

 richly-branched, wide-creeping mycelium. Nowakowski first 

 found them in decaying marsh-plants. Sporangia are either 

 terminal or interstitial. 



Of Cladochytrium iridis only resting spores were known, 

 see Fig. 4, 4. 



Cladochytrium graminis " attacks the root and leave 



FIG. 15. OLPIDIOPSIS SAPROLEGNIAE. A and B, stages of parasites in 

 the same host -filament ; C, in a host-filament, the protoplasm of 

 which is exhausted, are six parasites at different stages, the uppermost 

 discharging zoospores ; below, zoospores more magnified ; D, part 

 of a filament with empty sporangia ; E, at the end of a filament are 

 two parasites with prickle-walls, and spore-ducts ; F, four zoospores ; 

 G-I, stages of the same three parasites in the same host-filament. 

 A-D, after M. Cornu ; E-I, after A. Fischer. Reduced to f. 



of different kinds of lawn and pasture grasses : the disease 

 spreads from a centre, killing off the herbage and leaving 

 naked patches. ... If the dead basal leaves are examined, 

 the tissues more especially along the edges of the leaf, are 

 seen to be crowded with the resting spores of the fungus " 

 (Massee). 



