42 THE JOURNAL OF BOTANY 
Before pointing out the characteristics of F. Polygont in its 
conidial stage, and showing why under certain conditions it has 
been mistaken for an Ovularia, it will be well first to mention 
another fungus, lately published as Ovularia Clematidis Chittenden.* 
This fungus was collected at Chelmsford, Essex, in Sept. 1903, on 
the flowers of Clematis Jackmanni. The mycelium formed whitish 
conidia 
which sometimes give indications of being shortly catenulate.”’ 
Some of the figures given illustrating the fungus are reproduced at 
Plate 469, fig. 2. 
Here again the fungus is clearly the conidial stage of E. Poly- 
gont, a species which has been recorded on several members of the 
genus Clematis. 
Oidium form of many species of the Erysiphacea, where the conidia 
are concatenate in long chains.” I should like here to call special 
7 
tw nidi 
. If, however, this Oidium is cultivated on leaves surrounded 
by a damp atmosphere, conidiophores bearing a chain of conidia, 
3-6, or even more, in number, will be produced (fig. 10). 
As regards FE. Polygoni, the form on Ranunculus shows in the 
conidial stage conidiophores bearing frequently only a single ripe 
conidium at the apex (fig. 8); ripe conidia in chains of two or three 
. 
xxviii. p. elxxvii, fig 
t See ‘* Monograph of the Erysiphacee,” p. 179 (M : 
vol. ix. (1900) ). y P (Mem. Torrey Bot. Club, 
} Bull, Torrey Bot: Club, xxix. 187, pl. 9, figs. 1, 2, 8, 
* Gardeners’ Ghrosiele, xxxiv. 299 (1903). See also Journ. Roy. Hort. Soe. 
