68 DISEASES OF FIELD & GARDEN CROPS. [CH.XII. 



celium formed a dense transparent stratum over the host 

 plant. In some places the parasite was colourless, like 



FIG. 24. 



Parasite of Isaria fuciformis, B. ; Saprolegnia philomukes, W.Sm. 

 Enlarged 400 diameters. 



the better known species of Saprolegniece ; in other places 

 it was rose-coloured, from its absorbing the colour of the 

 red Isaria. 



Saprolegnia philomukes, W.Sm., zoosporangia, very large, 

 thick-walled, sessile, shortly stalked, or intercalated in the 

 mycelium, sometimes confluent with each other, all bear- 

 ing zoospores, which often germinate whilst still in situ. 

 Antheridia elongated, rare ; mycelium profusely septate, 

 somewhat torulose, filled with colourless or rose-coloured 

 protoplasm, and bearing many small abortive sporangia 

 or conidia. 



We have seen a similar plant on fungi, with oospores 

 as well as zoospores. 



