The Scottish Naturalist, 79 



Cystopus Lev. 

 C. candidus (Pers.) Lev., 1, 2, 3, 4, 5, 6, S, 10, plentiful. 

 Has been observed on 

 Barbarea vulgaris. 

 Cardamine hirsuta and C. Hexuosa. 

 Sisymbrium officinale. 

 Brassica Rapa and B. Sinapistrum. 

 Cochlearia officinalis and C Armoracia. 

 Capsella Bursa-pastoris. 

 C. TragopogOIlis (Pers.) Schr. (C. cubicus Str., No. 1306 in 

 Mycol. Scotica), 5, on Tragopogon pratensis. 



0. spimilosus De Bary. 5, 7, local, but plentiful where it 



occurs, on Cnicus lanceolatus, C. palustris, and C 

 arvensis. 



Phytophthora De Bary. 



P. infestans Mont. (zzPeronospora infestans Mont, No. 1443, 

 Mycol. Scotica.) -1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14; 

 too plentiful on stems and leaves of Solarium tuberosum 

 (Potato). 



Peronospora Corda. 



Sect. I. Plasmopara Schroeter, Basidia with few branches, 

 which are simple, or each bear two or three straight, 

 simple branchlets, or are (rarely) once bifurcated before 

 bearing these. Conidia bear a papilla at the tip ; in 

 germination the contents escape as a mass of proto- 

 plasm, or as zoospores ; Oospores round, with thin, 

 smooth wall. 



1. P. nivea Unger. 1, 5, 7, 8. Abundant in many places. Has 



been found on 

 Sanicula Europcea, Invermay, near Perth (Dr. F. B. White). 

 Conium maculatum, near Aberdeen, a very slightly branched 



and rather peculiar variety. 

 JEgopodium Podagraria, common. 

 Myrrhis odorata, near Aberdeen. 

 Anthriscus sylvestris, plentiful. 

 Meum Athamanticum, in Braemar. 

 Angelica sylvestris, common. 



2. P. pygmaea Unger. 7, 8. Abundant in summer on Anemone 



nemorosa. Oospores occur plentifully in the leaves, as 

 was first observed in Scotland by Mr. G. Brebner. 



