272 M. E. P. Fries on the Geographical 
as the basis for their systematic distribution, we find considerable 
and essential differences in the manner in which that process is 
effected present themselves, suggesting a useful division of the 
Fungi into three subclasses, as follow :— 
‘1, Fungi properly so called, adopting this appellation in its 
oldest sense and according to prevailing usage. They are recog- 
nized by their hymenium (proligerous lamina) bearing free spores, 
commonly attached in groups of four at the summit of the 
sporophores. The most highly developed types and the most 
important Fungi appertain to this subclass, and are further 
notable in presenting no near affinity either with Lichens or — 
with Algze. 
2. Semi-Fungi (Mycetes), which also possess a distinct pro- 
ligerous lamina, but have their spores habitually enclosed, in 
groups of eight, within enclosed sacs or asci. This subclass is 
constituted of the Discomycetes and Pyrenomycetes, which ex- 
hibit a transition towards the Lichens, with the fructification of 
which they present the closest resemblance. 
**3. Moulds (Mucedines), or Fungi destitute of a proligerous 
lamina, and which are allied by insensible transitions either to 
the Byssaceze or, more particularly, to the lower Algz, from 
which, in many cases, they are undistinguishable except by ha- 
bitat and other biological characters.” 
Before entering on the account of the distribution of the 
Fungi, especially of their higher forms, throughout the different 
regions of the globe, we will point out, in a few words, what are 
the countries respecting which we have information on this sub- 
ject, and what is the value of that knowledge. In Europe, 
Scandinavia and England are the countries most thoroughly 
and exactly known ; and next to them certain portions of France, 
of Germany, of Italy, of Switzerland, and the environs of St. 
Petersburg may be mentioned. As to America, many remark- 
able Fungi have for a long time been known to flourish there, 
Bosc was the first to furnish some special though imperfect no- 
tices of American Fungi; but Schweinitz may be looked upon 
as having been the true founder of American mycology, by the 
publication of his work on the Fungi of Carolina and of the 
United States generally. Several distinguished naturalists oc- 
cupied in the special study of mycology are to be found in 
America, among whom Messrs. Curtis, Ravenel, and Lecomte may 
be named. Some considerable collections have, moreover, been 
transmitted to Europe by different travellers from the United 
States and Mexico, and have been described by Berkeley, Mon- 
tagne, and Fries. Central and Southern America have equally 
furnished rich collections, which have reached Europe and been 
described by the same writers, The other portions of the world 
