The first of these (Protobasidiomycetes) includes the following distinct groups: (1) the Uredineæ, "Rust Fungi," which have horizontally divided basidia, always free, never enclosed; (2) the Auricularieæ, having basidia somewhat resembling those of the Uredineæ, but which are borne in fruit bodies with open hymenia; (3) Pileacreæ, having horizontal septate basidia in closed receptacles; and (4) Tremellineæ, having vertically divided basidia borne in gymnocarpous receptacles—that is, those in which the hymenium is exposed while the spores are growing.
The Autobasidiomycetes are characterized by undivided basidia, bearing spores only at the apex. This group is subdivided into three sections: (1) Dacryomycetes, which includes the lowest of the Tremelloid forms, with club-shaped basidia, nearly approaching the true Hymenomycetal type, together with several groups of minor import; (2) Gasteromycetes; and (3) Hymenomycetes, with Phalloideæ placed in the group as a subsection of Gasteromycetes.
The above can only be considered as a very brief abstract of the system of classification proposed by Dr. Brefield, but it will serve to give some idea of the principle on which the system is based, which is sufficient for our present purpose. Those who wish to study the system in detail will find it treated in a comprehensive manner in Dr. Von Tavel's summary as it appears in the Vergleichende Morphologie der Pilze, Jena, 1892.
CONIOMYCETES AND HYPHOMYCETES.
In the original classification of Fries two of the primary divisions of the sporiferous Fungi were termed, respectively, Coniomycetes and Hyphomycetes. This arrangement was accepted by Berkeley, the term Coniomycetes being applied to all fungi in which the naked spores, appearing like an impalpable dust, were the principal feature of the plant, and the term Hyphomycetes to fungi in which the threads or hyphæ bearing the spores were the most conspicuous feature.
Coniomycetes, as broadly interpreted by Berkeley and other mycologists of his day, included the Uredineæ or "rust fungi," the Ustilagines or "smut fungi," the Sphæropsideæ, and the Melanconieæ. This arrangement was very unsatisfactory on account of the distinctively different character of the methods of reproduction of the respective groups, and they have since been disassociated and by some authors ranked as distinct orders or families. Others combine Uredinei and Ustilaginei in one group under the name Hypodermei.
Familiar examples of Uredinei are seen in the rust of the Barberry leaf, etc., and of the Ustilaginei in the "smut" of corn and the "bunt" of wheat.
Some authors combine the Sphæropsideæ with the closely allied Melanconieæ. M. C. Cooke contends that the Sphæropsideæ should be considered apart from the Melanconieæ, on the fundamental basis that the former possess a distinct perithecium, while the latter do not.
The Sphæropsideæ as recently defined by Cooke are "Fungi possessed of a perithecium, but without asci, ... sporules or stylospores being produced internally at the apex of more or less distinct supporting hyphæ or pedicels, termed sporophores."