300 THE ESSEX NATURALIST
time active spore discharge continued. At the end of the
period 8 gm. had been transpired. Further, the apothecium
appeared completely normal and healthy. It was found to
weigh 0.8 gm. That is to say, during these four days it
had transpired about 10 times its own weight of water. This
must have come from the reservoir in the potometer. I think
it probable that the conduction of water in this fungus is
by capillarity between the hyphae of the stalk, which clearly
acts as a wick. It should be noted, however, that this kind
of conduction is possible only if free water is available
around the base of the fruit-body.
Some higher plants—the cacti in particular—are succulent
Xerophytes. They carry on their vital activities undiminished
during periods when no water is available in the soil. This
is possible because of the considerable water-reserve in their
tissues. Amongst Cup Fungi, Bulgaria inquinans can be
looked upon as a succulent xerophyte. If a section of an
apothecium is examined, the hyphae are seen ramifying in
a soft jelly. This jelly is the water reserve. If a fully-
imbibed specimen is exposed to dry air, it loses water by
evaporation and decreases in weight. If at the same time
its spore-output is measured, it is found to go on discharging
its spores until it is only about a fifth of the original weight
and has a very shrivelled appearance.
Again, a few Cup Fungi seem to be Xerophytes of the
drought-enduring type. A common example is Tricho-
scypilella, which occurs so commonly as minute orange cups
with white margins on fallen twigs and branches of larch.
Under dry conditions the apothecia lose water and shrivel.
On moistening, they rapidly revive. This type, although
comparatively rare amongst the Discomycetes, is common
amongst the numerous Pyrenomycetes that are to be found
on wood and bark.
Apart from the coprophilous species, in which aerial
transport is of little importance, dispersal of spores in
Discomycetes is essentially by wind. However, Cup Fungi
are by no means limited to the terrestrial environment.
There seems to be quite an extensive flora of submerged
aquatic species, although this flora is by no means fully
known. These fungi are to be found particularly in lakes
and tarns. I know them best from the English Lake Dis-
trict. They normally grow completely submerged. The