276 FUNGI. 
The Tuberacei* are remarkable amongst the fungi in being 
all of them more or less hypogeous. They are natives of warm 
countries, and are distributed into numerous genera and species. 
The Tuberacei constitute in Northern latitudes a group of fungi 
very poor in specific forms. The few species of the Hymeno- 
gastres belonging to Sweden, with the exception of Hyperrhiza 
variegata and one example of the genus Octaviana, are confined 
to the southern provinces. The greater part of this group, like 
the Lycoperdacei, are met with in the temperate zone. Most 
examples of the genus Lycoperdon are cosmopolitan. 
The Midulariacet and the Trichodermacet appear to be scat- 
tered over the globe in a uniform manner, although their species 
are not everywhere similar. The same statement applies to the 
Myxogastres, which are common in Lapland, and appear to have 
their central point of distribution in the countries within the 
temperate zone. At the same time, they are not wanting in 
tropical regions, notwithstanding that the intensity of heat, by 
drying up the mucilage which serves as the medium for the 
development of their spores, is opposed to their development.t 
Of the Coniomycetes, the parasitic species, as the Ceomacei, the 
Pucciniei, and the Ustilagines, accompany their foster-plants into 
almost all regions where they are found ; so that smut, rust, and 
mildew are as common on wheat and barley in the Himalayas 
and in New Zealand as in Europe and America. Raveneliaazd 
Cronartium only occur in the warmer parts of the temperate 
zone, whilst Sartvellia is confined to Surinam. Species of 
Podisoma and Restelia are as common in the United States as 
in Europe, and the latter appears also at the Cape and Ceylon. 
Wherever species of Spheria occur there the Spheronemet are 
found, but they do not appear, according to our present know- 
ledge, to be so plentiful in tropical as in temperate countries. 
The Torulacei and its allies are widely diffused, and probably 
occur to a considerable extent in tropical countries. 
Hyphomycetes are widely diffused; some species are peculiarly 
* The Hypoget are evidently intended here by Fries, 
+ Fries, ‘‘On the Geographical Distribution of Fungi,” in “ Aun. and Mag. 
Nat. Hist.” ser. 3, vol. ix. p. 285. 
