Distribution of Fungi. | 275 
stance is indicated by the fact that their most remarkable species 
make their appearance ordinarily in early spring, as is observed 
in the case of Helvella, Morchella, Verpa, Discina, and in many 
of the largest and most beautiful Pezize, which, like the Peziza 
tuberosa, P. acetabulum, P. melena, P. coccinea, P. majalis, P. 
protracta, &c., show themselves frequently during the melting 
of the snow. 
Notwithstanding these differences, all the principal groups of 
semi-Fungi, and their large genera, are common to every 
country on the globe. Some genera, less rich in species, though 
remarkable in many points, belong exclusively to particular 
countries: thus, among the Pyrenomycetes, the genus Cyttaria is 
found to be limited to the region of the Antarctic beech-trees ; and 
among the Discomycetes, the genus Spadonia has been observed 
only in Brazil. Many, however, generally reputed to be peculiar 
to certain countries, have at a later period, by means of more 
attentive researches, been discovered elsewhere,—as, for example, 
the genus Urnula, which was at one time considered peculiar to 
North America, is found to be represented by the Urnula minor in 
Guinea. In the same way another genus of North America has 
been discovered by M. Lindblad in Sudermania. 
.. Among the Pyrenomycetes there are not a few very remark- 
able genera peculiar to tropical countries; such are Thamno- 
myces, Camillea, Kretschmaria, Leveillea, &c., and probably many 
others yet unobserved amid the rich vegetation of those regions, 
An attempt to point out what genera of Pyrenomycetes are there 
absent would be too daring a proceeding in the present imper- 
fect state of our acquaintance with respect to the Micromycetes 
of those countries ; for these productions of the vegetable world 
are rarely gathered by travellers, to whom it is that we are in- 
debted for the materials for our study. What strikes the atten- 
tion of the observer is the circumstance that several large genera 
of Fungi evidently correspond to each other, one in the torrid, 
another in the temperate zone; for example, in the temperate 
zone, the Erysiphe are evidently the analogues of the Meliole, 
which inhabit the torrid zone. 
The Tuberacez, properly so called, must be placed with the 
Mycetes (semi-Fungi), by reason of their spores being enclosed 
within thece. Although at first sight they resemble rather the 
Gasteromycetes, and, by their mode of evolution, the Hymeno- 
gastres, still their fructification is so different that they must be 
referred to the division before named. There are also inter- 
mediate forms between the Tuberacez and the other semi- 
Fungi—as, for instance, certain hypogeous Pezize, such as the 
Peziza sepulta, which makes its appearance yearly, after the 
copious rain of autumn, in the sanded avenues of the Botanical 
