CERTAIN BRITISH HETERCECISMAL URED1NES. 165 
finding the teleutospores of this paraphysed Uredo to be a 
Uromyces they were found to be those of a Puccinia. Further 
search was rewarded by gathering the last year’s teleutospores 
sparingly upon the Poa, but abundantly upon the other two 
grasses. These Puccinia spores germinated well, and were used 
in the following experiments. In both localities above referred 
to numerous plants of Ranunculus acris were found in 
close proximity to the grasses affected with the iEcidium. 
The germinating teleutospores from the last year’s Puccinia 
from the Poa (?) Avena elatior and Alopecurus were applied 
to R. acris (373, 381, 382, 383, 388, 389), and in every 
instance the iEcidium was produced. Here, then, was quite 
an unexpected discovery, that instead of the iEcidium on 
R. acris being connected with a Uromyces at all, it was 
connected with a Puccinia. Conversely the aecidiospores in 
question were placed upon Alopecurus (401, 402, 404) and 
Avena elatior (405), with the result of giving rise to a Uredo, 
followed in due course by the Puccinia. This Uredo, however, 
strange to say, was never once accompanied by any paraphvses 
at all. This puzzled me very much, for the paraphysed Uredo 
as it occurred naturally was always accompanied by the 
Puccinia, but by culture the result was invariably as above 
stated. The possibility of this Puccinia giving rise to a para- 
physed Uredo upon some other graminacious host suggested 
itself. The secidiospores from Ranunculus acris were, 
therefore, applied to Poa trivialis (364), P. nemoralis 
(367), P. pratensis (365, 366), P. compressa (?) (378), 
Dactylis glomerata (379), Lolium perenne (377, 403), 
upon all of which paraphysed uredospores are known to occur, 
but in every case without any result. 
Ranunculus acris was infected with the germinating 
teleutospores of Uromyces dactvlidis (250, 271) but with 
no success, as was also the case when P.Magnusiana (360) was 
employed. Puccinia perplexans bears a strong anatomical 
resemblance to P. rubigo-vera, the most obvious difference 
being that the last-named species has its teleutospores sur- 
rounded by a bed of dark brown paraphyses. In point of fact 
