242 



A. Barclay— Dftscry*/M'c L!st of the Urcdino.T [No. 2, 



tlic winter, and, indeed, do not fall off until the rains commence, wlien 

 tlicy fall, but by this time new young leaves have already been unfold- 

 ed. It would thus appear that the teleutospores germinate at the com- 

 mencement of the rains, infecting the new leaves, though a few experiments 

 I made with a view to verifying this did not succeed.* If infection 

 of the new leaves by the teleutospores on the old ones does actually take 

 place, we have an autoacious Uredine in which the rocidial fructification 

 has dropped out, for I am quite certain that no recidium is produced by 

 this fungus. It, however, remains to be proved that the teleutospores 

 give rise to the production of uredospores. In the meantime, the fungus 

 must bo classed with such forms as P. suaveolens, (Pers.), P. OreosUni 

 (Strauss), and P. Vinco', D. C, among the Eemipuceinia, all of which 

 produce spermogonia together with uredo- and teleuto-spores, without 

 any ajoidium. 



The teleutospores are plump brown spores, constricted at the sep- 

 tum, with well marked apical thickening, which is rounded usually, but 

 which is sometimes conical either in the centre or laterally. The lower 

 cell narrows towards the stalk, which is long and adherent. The surface 

 of the epispore is smooth (Fig. 14, PI. XII). Each cell usually displays a 

 clear nuclear vesicle. The freshly gathered spores, when moistened, 

 measure from 49 to 54 fi in total length (upper cell from 25 to 30 /jl, and 

 lower 24 fi) and 13 to 15 at the septum. The apical thickening is 8 

 to 9 /i in depth. 



Itemarks.—I have called this P. Jwlvetica with some hesitation. In 

 the European species no mention is made of the existence of spermogo- 

 nia, a prominent and invariable feature in the Simla species ; but the 

 measurements of the uredo and teleutospores correspond fairly well. 



11. PucciNiA Menthj), Pers. 

 on Origanum vulgare, Linn. 

 While writing this list, I found, in March, this host harbouring a 

 Pitccmm-bearing fungus. Some plants were very extensively attacked, 

 bearing dark brown pustules on the under surface of the blade. The 

 pustules are small, round, and hemispherical, and do not tend to coalesce. 

 Sometimes each leaf bears a very large number of such isolated pustules, 

 sometimes only one. The position of these pustules is indicated on the 

 upper surface of the leaf by dark spots surrounded by a zone of slight- 

 ly paled tissue. The pustules contain both brown uredospores and 

 teleutospores, the former the more numerous (at this season at any 

 rate). Both spores are very easily detached from the spore bod. 



* As this paper was passing throngh the press, I succeeded in reproducing the 

 nredo stago with the sporidiu of teleutospores gathered iu the preceding autumn. 



