PLATE 4 

 PERONOSPORACEAE 



(a. Conidiophore and conidia x200; b. Mature conidia x500; 

 c. Oospore x500; except as otherwise indicated) 



1. Albugo Candida (Pers.) Gray 



(Schroet. Nat. Ptl. p. Ill, after DeBary) 



a. Conidiophores and conidia 



b. Formation of zoospores 



c. Oospore 



2. Bremia lactucae Regel 



a. (Fl. Nebr. pi. 16, after F. E. Clements) 



b. (Schroet. lb, p. 117) 



c. (Fl. Nebr. Id.) 



d. Tip of conidiophore (Schroet. lb.) 



3. Plasmopara halstedi (Earle) Berl. & De Toni 



(Fl. Nebr. Id.) 



4. Sclerospora graminicola (Sacc.) Schroet. 



(Id.) 



5. Peronospora parasitica (Pers.) Fr. 



(Id.) 



6. Phytophthora infestans (Mont.) DeBary 



(Schroet. lb. p. 113, after DeP.ary) 



b. Exit of zoospores x390 



c. Zoospores x390 



7. Basidiophora entospora Roze & Cornu 



(Id. p. 114, after Cornu) 



b. Zoospore formation x3()0 



c. x300 



8. Monoblepharis sphaerica Cornu 



(Id. p. 107, after Cornu) 

 a., b., c, Stages in the development of oogone and 

 antheridium x800 



9. Gonapodya prolifera (Cornu) A. Fisch. 



(Id., after Reinsch) 



a. Cluster of empty and proliferating zoosporangia 



b. Zoospores in sporangium x240 



