CLUSTER-CUPS. 23 
parasite without regard to the identity or distinctness of the 
plant upon which it is parasitic. 
Before the JEcidium breaks through the epidermis the 
under-surface of the leaves of the goatsbeard will appear to be 
covered with little elevations or pustules, paler at the apex ; 
these soon become ruptured, and the fungus pushes its head 
through the opening, at the same time bursting by radiating 
fissures. The teeth thus formed resemble those of the 
peristome of some mosses. All around the orifice of the 
peridium the teeth become recurved, and the orange spores 
are exposed, crowded together within. At first, and while 
contained within the peridium, these spores are concatenate 
or chained together, but when dispersed they are scattered 
singly about the orifice, often mixed with the colourless 
cells arising from the partial breaking up of the teeth of the 
peridium. 
Let us pause for a moment in our examination of the 
individual cups, to ascertain their manner of distribution over 
the leaves. In this instance they are scattered without any 
apparent order over the under- surface, but generally thickest 
towards the summit of the leaves ; occasionally a few are met 
with on the upper surface. Sometimes two or three touch at 
the margins, but we have never met with them truly confluent ; 
generally there is a space greater than the width of the cups 
around each, the stratum or subiculum from whence they 
arise is scarcely thickened, and there are no spots or indica- 
tions on the opposite surface. If a leaf be taken fresh and the 
cuticle stripped off, which it will sometimes do very readily, 
the orifices through which the M cidium has burst will appear 
in irregular holes. If a section be made of one or two of the 
fungi in situ, they will be seen to spring from beneath the 
cuticle, the peridium to be simple, and rounded at the base, 
the spores clustered at the bottom, and the fringe to be a 
continuation of its cellular substance. 
The spores in this species are orange, subglobose, sometimes 
angular, and indeed very variable both in size and form, 
though the majority are comparatively large. Each of these 
bodies is, doubtless, capable of reproducing its species, and if 
we compute 2,000 cluster- cups as occurring on each leaf, and 
we have found half as many more on an ordinary- sized leaf, 
and suppose each cup to contain 250,000 spores, which again 
is below the actual number, then we shall have not less than 
five hundred millions of reproductive bodies on one leaf of the 
goatsbeard to furnish a crop of parasites for the plants of the 
succeeding year. We must reckon by millions, and our 
figures and faculties fail in appreciating the myriads of spores 
which compose the orange dust produced upon one infected 
