479 
THE WHITE RUST, ETC. 
family, all suffer more or less from its roving disposition. The 
mycelium of whitish threads is even more conspicuous than in 
the last species, but the conceptacles are often not to be found 
at all. These are also very minute and most common on the 
under surface of the leaves. The appendages, or fulcra, are 
simple, floccose (fig. 1), and coloured. The sporangia are found 
singly in each conceptacle, and each sporangium contains eight 
spores. 
An autumnal stroll amongst hazel-bushes, when the nuts 
are ripe, will lead, if the nuts are not a greater attraction, to 
the discovery of whitish patches on the under surface of the 
leaves, caused by the mycelium of the hazel mildew (Phyllactinia 
guttata, Lev.) These patches are less distinct and conspicuous 
than in many other species, but the little blackish dots of the 
conceptacles may be distinguished by sharp eyes without the 
use of the lens. Though possessing a decided preference for 
the hazel this species is also found on the green leaves of the 
hawthorn, ash, elm, birch, sallow, beech, oak, and hornbeam. 
The conceptacles are larger than in the two preceding species, 
and somewhat depressed above. The appendages are few 
(fig. 4), radiating, rigid, and acicular, or like needles. Each 
conceptacle contains eight or more sporangia, and each spo- 
rangium has from two to four spores (fig. 5). This species 
being very common, its conceptacles large, and produced 
copiously, and its appendages distinct, it will prove a good 
type with which the student of these fungi may commence his 
examinations. This is the only representative which we possess 
of the genus established by M. Leveille for such of the Erysipliei 
as have the conceptacle depressed, and the appendages rigid 
and simple, by which features it is distinguished from genuine 
species of Erysiphe. 
Two species, also common, having many features agreeing 
with each other, are found on the leaves of the maple and the 
willow. The willow blight ( Uncimda adunca , Lev.) is found 
irrespectively on various species of poplar and willow (fig. 6). 
In size and external appearances, to the unaided eye, it seems 
scarcely to differ from the preceding, but more minute examina- 
tion will show that in the appendages there is an appreciable 
difference. Still rigid, but no longer aciculate, the tips bent 
or curved like a little hook, or curled upon themselves (fig. 8), 
radiating and numerous (fig. 7), and at length tending upwards. 
Many sporangia are contained within each conceptacle, each of 
which is furnished with four spores. The amateur must not 
be disappointed, if, on examining mature conceptacles with a 
view to the discovery of the sporangia, he finds only free spores. 
The membrane of the sporangia is very delicate, and disappears 
generally as the spores are matured. 
