Classification, 115 



carrying tlie subspherical gonidia. Oospores minute, 

 globose, epispore rugulose, yellow-brown. 



Bremia, Kegel, in Bot. Ztg. 1848, p. 665 ; Sacc. 

 Syll. vii. p. 243. 



Peronospora of various authors. Characterized by 

 the much branched gonidiophores, subglobose, 

 paj^illate gonidia, and small oospores. 



Bremia lactucse, Kegel (figs. 64 — 65). 



Mycelium stout, often variously twisted, haustoria 

 subclavate, simple ; gonidiophores 2 — 6 times dichoto- 

 mously, or sometimes trichotomously, branched, stem 

 and primary branches inflated above, the ultimate 

 branchlets inflated at the tips into subclavate or sub- 

 globose vesicles, bearing 2 — 8 minute, conical spicules, 

 each carrying a subglobose gonidium, with a broad, 

 depressed, apical papilla, 16-23 yu. diameter ; 

 oospores globose, yellow-brown, pellucid, rugulose, 

 25-35 fi. 



Bremia lachicce, Eegel^ Bot. Ztg. 1843, p. 665, t. 3, 

 f. B. ; Sacc. Syll. vii. p. 243. 



Peronospora gangliformis, Cke. Hdbk. n. 1777; 

 Cke. Micr. Fung. t. 14, f. 265. 



On living leaves of various composite plants, as 

 illustrated by the following genera, — Lactuca, Senecioj 

 Helichrysum, Cirsium, Centaurea, Lapsana, Leontodon, 

 Tragopogon, Hypo cheer is, Mulgedium, Sonchus, Crepis, 

 and Hieracium. It is also common on garden lettuce 

 Lachica scariola^ var. sativa. 



Peronospora, Corda. 



Mycelium generally furnished with filiform 

 branched haustoria ; gonidiophores solitary or fasci- 



I 2 



