354 MELAMPSORA 



short chains, without paraphyses, roundish to ellipsoid, densely 

 verrucose, 21 — 28 x 19— 24/u,.] 



Uredospores. Son hypophyllous and on the stems, scattered 

 roundish or oblong, soon naked, but surrounded by the epider- 

 mis, golden-brown, mixed with numerous capitate paraphyses; 

 spores roundish, orange. I ~> —17 x 11 — 14/a: epispore colourless, 

 echinulate, without perceptible germ-pores; paraphyses hyaline, 

 with strongly thickened heads, 16 — 23 (m diam. 



Teleutospores. Sori amphigenous, subepidermal, minute 

 rmindish or oblong, reddish-brown, then black, more or less 

 pulvinate, on the stems often confluent; spores prismatic, 50 — 

 60 x 10 — 14 fx: epispore brown, thin, at length thickened above 

 (up to 5 /x) and darker. 



On Euphorbia eodgua, E. Helioscopia, E. Peplus. May- 

 October. Very common. (Fig. 264.) 



Miiller, on the ground of cultures, considers the form on E. Helioscopia 

 as a separate species from those on E. Peplus and E. exigua, the latter 

 two also being biologically distinct from each other (Centralbl. f. Bakter. 

 2. xix. 441;. In his experiments he observed a caeoma-stage on E. exigua 

 which the others did not have. This stage seems to be very rarely met 

 with, and has probably not occurred in this country : the description of 

 the spermogoues and cseomata is from Fischer. In the same species, as it 

 occurs on E. Cyparissia.% Jacky states that he obtained the uredospores 

 by infection with the basidiospores without the intervention of the 

 cseoma-stage, so that M. Euphorbias may be in a transition state between 

 a eM-form and a kemi-fovva. The secidium on E. exigua recorded by 

 Plowright (I.e. p. 270) belongs to Uromyces tuberculatus ; see p. 102. 



Distribution : Europe, Siberia. 



13. Melampsora Hypericorum Wint. 



Uredo Hypericorum DC. Flor. fr. vi. 81. Cooke, Handb. p. 526 : 



Micr. Fung. p. 215, pi. 8, f. 174. 17-">. 

 Melampsora Hypericorum Winter, Pilze, p. 241. Plowr. Ured. p. 243. 



Sacc. Syll. vii. 591. Fischer, Ured. Schweiz, p. 506, f. 317. 



McAlpine, Rusts of Australia, p. 191. 



jEcidiospores. Cseomata hypophyllous, scattered, roundish 

 or oblong, flatly pulvinate, often very small, subepidermal, long 

 covered, at length erumpent, orange, showing as indefinite pale- 

 yellow or orange spots on the upper face; spores in short 



