1 12 « i UROMYCES 



Teleittospons. Sori generally hypophyllous, similar to the 



uredo-sori but more often confluent, 

 always covered by the epidermis, 

 compact . shining, black; spores ovate- 

 oblong, occasionally ellipsoid or pyri- 

 form, rounded above, rarely truncate, 

 often slightly thickened (up to 4//,), 



Fig. 77. U. Dactylitis. Te- smooth, yellow-brown, darker only 

 leutospores and the accom- along the summit, 18 — 30 X 14 — 

 panying paraphyses. . ,. , ,. , 



20//,; epispore H/u, thick; pedicels 



brownish, persistent, nearly as long as the spore; paraphyses 

 numerous, brown, agglutinated, dividing the sori into compart- 

 ments. 



. Ecidia on Ranunculus acris, R. bulbosns, R. repens, March — 

 May: uredo- and teleutospores on Dactylis glomerate,, from 

 July onwards, often covering the leaves, less often the sheaths 

 and culms, and persisting through the winter, especially on the 

 latter. (Fig. 77.) 



This species and the following (U. Poae) are very closely allied, and 

 should possibly be united. Perhaps more experimental cultures have been 

 carried out with these two species than with most other Uredines ; but the 

 result is only a wild confusion of contradictory statements, from which 

 one can infer, either that an immense number of intricately connected, but 

 morphologically indistinguishable forms, inhabit the species of Ranun- 

 culus and of Poa and Dactylis — or, preferably, that the factors which 

 govern the success of an attempted infection are so numerous and so little 

 known, that failure does not afford any ground for arriving at a definite 

 conclusion. Those who wish to learn further should consult the long 

 account of these results given in Sydow, Monographia, ii. pp. 312 — 16. 



In the British specimens of U. Dactylidis which I have examined, the 

 paraphyses in the teleuto-sori, though often overlooked, are a conspicuous 

 feature. But upon the question of paraphyses in the uredo-sori no agree- 

 ment has been arrived at ; the various authorities flatly contradict one 

 another. Either, therefore, the paraphyses occur differently in different 

 countries, as Plowright suggests, or more than one species is included 

 under this title, or their presence or absence is a matter of no importance. 

 Against the latter suggestion, however, we must set the fact that in other 

 cases, e.g. in Puccinia Sonchi, the paraphyses form a constant and dis- 

 tinctive character. 



An secidium occurring on Ranunculus acris belongs to Puccinia 

 perplexans Plowr., but cannot be distinguished from the present one, 



