328 
POPULAR SCIENCE REVIEW. 
burst through the cuticle, and appear on the young branches 
of wild roses, extending sometimes for two or three inches in 
length (Plate XII. fig. 1 8), and form one of the most beautiful 
and obtrusive of the dust-like fungi. It is not confined to 
roses ; but the meadow-sweet, on which it is also found, does 
not grow in localities where its parasite is so liable to meet the 
gaze of the ordinary wayfarer. The habit of this rust is more 
or less that of those which are associated with it. The pustules 
are not small and orbicular as in most instances in other 
groups (except Polycystis ), but are large and irregular, and 
generally but few together or single. The spores are variously 
coloured, and have peduncles, or footstalks, of a greater or 
less length. In the rose rust these spores are profuse, but the 
peduncle is short (Plate XII. fig. 19). 
Plants of the pea and bean tribe are liable to be attacked by 
one of these rusts, and in this instance the spores are so cha- 
racteristic that no one could well confound them with any 
other. Externally it appears as an irregular brownish pustule, 
breaking through the epidermis as an impalpable powder, not 
unlike a pinch of “brown rappee” snuff. The spores are 
ovoid, with a very long peduncle, whence its name ( Uromyces 
apjoendiculata ) . It appears on a great variety of plants, but 
from the peculiarity of the spores (Plate XII. fig. 21), is easily 
recognized. Our figure represents it on the leaf of a vetch 
(Plate XII. fig. 20). 
An allied species, and a beautiful one, is to be found on the 
stinking iris (Iris foetidissima ) , and another on the under 
surface of the leaves of primroses. 
The pilewort ( Ranunculus ficaria) we have already seen 
attacked by one species of microscopic fungi, and I have now 
to record the occurrence of another. Some plants appear to 
be destined both alive and dead to become the prey of others. 
The common nettle, for instance, as if in retribution for the 
annoyance it often occasions on account of its stinging pro- 
pensities, has not less than twenty different species of minute 
fungi, to say nothing of coleopterous and lepidopterous insects, 
which make a home, sometimes upon its green leaves, and 
sometimes on its dead stems. We might almost state that it 
has a flora and fauna of its own. The pilewort too has many 
foes ; but these are fewer in number, and mostly attack the 
living plant. The cluster-cups I have noticed already ; some 
do not fall within the limits of this paper ; but one, which is 
found in May and June, belongs to this genus. It appears like 
a purplish-brown powder bursting through blistered spots on 
the leaves and footstalks (Plate XII. fig. 22). The spores are 
small, and are, of course, provided with pedicels (Plate XII. 
tig. 23). 
