ON GKAMINE.K 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 secidium. 



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 oecidial 

 host cannot be determined. A fifth race, P. Schmidtiana Dietel, having 

 its recidia on Leucojum, has not yet been found in Britain. 



Distribution: Europe and North America. 



(1) Puccini a Digraphidis Soppitt. 



JEcidium Convallariae Schum. Enum. PI. Sail. ii. 224. Plowr. Ured. 



p. 26-1. Soppitt in Gard. Chron. ser. 3, vii. 643. 

 Puccinia 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. 

 /'. Sinilacearum-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 oecidia. 



uEcidiospores. /Ecidia hypophyllous, loosely clustered on 

 roundish or irregular yellow spots, cup-shaped, with a cut white 

 revolute margin; spores verruculose, yellowish, 19 — 27 fx. 



/Ecidia 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 secidial hosts. But, 

 on the other hand, Klebahn lias been able to infect, from one and the 

 same Puccinia, both Convallaria, Maianthenmm, 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. 



