ON GRAMINEE 267 
The four following biological races agree exactly in the teleutospores, 
and these can only be distinguished by their successful use to infect 
the alternate host; though sometimes the question may presumably be 
decided by finding one or more of those hosts, in the immediate neigh- 
bourhood, affected by the ecidium. 
It is evident from the disagreement between various authors that it 
is impossible to decide to which of the four biological races the name 
P. sessilis Schneid. should be applied: it will be better, therefore, to use it 
as a collective title, which can be employed in cases where the xcidial 
host cannot be determined. A fifth race, P. Schmidtiana Dietel, having 
its ecidia on Leucojum, has not yet been found in Britain. 
DISTRIBUTION: Europe and North America. 
(1) Puccinia DicRapHipis Soppitt. 
Aicidium Convallariae Schum. Enum. Pl. Sill. ii. 224. Plowr. Ured. 
p. 264. Soppitt in Gard. Chron. ser. 3, vii. 648. 
Puceinia Digraphidis Soppitt in Journ. Bot. 1890, p. 213. 
P. intermixta Friend in Gard. Chron. ser. 3, viii. 270 p.p. 
P. Paridis Plowr. in Gard. Chron. 1892, p. 137; Journ. Linn. Soc. 
1893, p. 43. 
P. Smilacearum-Digraphidis Kleb. Zeitschr. f. Pflanzenk. 1896, p. 261. 
Fischer, Ured. Schweiz, p. 340, f. 251. 
P. sessilis Sydow, Monogr. i. 781. 
Spermogones. Epiphyllous or in the midst of the ecidia. 
Aicidiospores. /Ecidia hypophyllous, loosely clustered on 
roundish or irregular yellow spots, cup-shaped, with a cut white 
revolute margin; spores verruculose, yellowish, 19—27 p. 
fEcidia on Convallaria majalis, Paris quadrifolia. Not 
common. May and June. 
Attempts have been made to subdivide still further the fungi included 
under this head. P. Digraphidis Soppitt, on Convallaria, and P. Paridis 
Plowr., on Paris, are two of these forms which to their authors appeared 
under cultivation to be confined to their respective ecidial hosts. But, 
on the other hand, Klebahn has been able to infect, from one and the 
same Puceinia, both Convallaria, Matianthemum, Paris, and Polygonatum ; 
nevertheless his attempts to induce specialisation, by cultivating the 
fungus year after year on Polygonatum alone, had the result that towards 
the end (while it still grew freely on that genus) it could be transferred 
only with difficulty or not at all to the other genera. Evidently we have 
here a case where specialisation is naturally in progress, but has not yet 
proceeded far enough to effect complete separation. 
