154 
CHARLES B. PLOWRIGHT. 
Personal Investigations. — The above being the state of 
our information concerning the affinities of the Ranunculi 
iEcidia, the following series of experimental cultures have 
oeen made in the hope of definitely clearing up the matter. 
These were commenced in 1882 and continued through 
1883 and 84. 
Contradictory as the above views appear to be in many 
points, yet it will be seen that they are none the less in the 
main correct. 
In order to render this communication the more lucid at the 
expense of increasing its length to some extent, each species 
will be treated separately, and have appended to it a tabular 
statement of the cultures made respecting it. 
Uromyces pose, Rbh. — This Uromyces occurs in England 
very abundantly upon Poa trivialis, L., and P. pratensis, L. 
I have not met with it upon any other species of Poa nor upon 
any other grass. Of course it may occur upon other grasses, 
but I have never found it, nor have I been able to produce it 
upon any other. As Schroter has shown, its iEcidium is very 
abundant from February to May upon Ranunculus ficaria. 
But not only is R. ficaria its host, but also R. repens. 
This latter fact was suggested to me before I knew of Rostrup’s 
views from the profusion with which the above-named Poae 
were attacked by the Uromyces in localities in which R. 
ficaria did not occur, and in which R. repens did. A series 
of seven experiments were made, however, by placing the 
spores of iEcidium Ranunculi repentis upon Dactylis 
glomerata (Expts. 29, 30, 119, 122, 131, 153, 154) before 
Schroter and Winter’s statement that it is connected with 
Uromyces dactylidis was definitely rejected. The material 
employed in these experiments was not collected from a single 
locality ; on the contrary, specimens were procured from several 
places near King’s Lynn, and even from Shrewsbury, kindly 
sent to me by Mr. W. Phillips, F.L.S. Moreover, the iEcidium 
upon R. repens gave rise to no Uredo upon P. nemoralis 
(143) nor upon P. annua (155). Conversely the germinating 
spores of Uromyces dactylidis in five cultures upon 
