18 



BKEFIELD'S CLASSIFICATION OF FUNGF 



A s^^stem of classification of fungi which is receiving attention from 

 mycologists is that recently presented by the distinguished German au- 

 thor Dr. Oscar Brefield. Dr. Brefield's exhaustive investigations into the 

 life-history of fungi in general have been such as to entitle his views to 

 consideration, although the system presents some inconsistencies which 

 may prevent its adoption in its entirety. 



According to the Brefield system, as summarized by his colleague Dr. 

 Von Tavel, Fungi are divided into two primary classes : (1) the Phycomy- 

 cetes, or lower fungi nearest like the algse, consisting of a one-celled thai- 

 las vnth sexual as loell as nonsexual modes of rejyroductioot, and (2) the 

 Mesomycetes and the Mycomycetes, having a divided or many celled 

 thallus, propagated by non-sexually formed spores. The Phycomycetes 

 are further divided into two large sections, based on their methods of 

 reproduction, termed, respectively. Zygomycetes and Oomycetes. These 

 include the old typical Mucors, the Peronosporese or " rotting moulds," 

 once classed with the Hyphomycetes, the SajDrolegniacese, " Fish Moulds," 

 of aquatic habit, the Entomophthoracese, " Insect Moulds," together with 

 some minor groups. The Mesomycetes connect the Phycomycetes with 

 the Mycomycetes. The class Mycomycetes is primarily divided into two 

 sections, viz., Ascomycetes and Basidyomycetes, with the Ustilaginese, 

 " Smut Fungi," in Mesomycetes, forming a transitional group between 

 Phycomycetes and the Basidiomycetal group of the higher fungi. 



The Ascomycetes are primarily subdivided into Exoasci and Carpoasci, 

 groups based on the character of the asci. In the first, JExoasci, the asci 

 are naked and borne directly on the myceluim : in the second, Carp>oasci, 

 they are enclosed in a wrapper composed of fertile hyphse and sterile 

 threads, having also accessory fruit forms. The first includes Endomy- 

 cetes and Taphrinefe. In the second are included the groups Gymnoasci, 

 Perisporacese, Pyrenomycetes, Hysteriaceae, Discomycetes, and Helvel- 

 lacese. 



The Basidiomycetes characterized by the possession of basidia are 

 arranged in two groups, based on the character of the basidia: (1) the 

 Protobasidiomycetes, in which the basidia are septate, divided, and (2) 

 the Autobasidiomycetes, in which the basidia are not divided, and bear a 

 definite number of spores. 



The first of these (Protobasidiomycetes) includes the following dis- 

 tinct groups: (1) the Uredinese, "Rust Fungi," which have horizontally 

 divided basidia, always free, never enclosed : (2) the Auriculariese, having 

 basidia somewhat resembling those of the Uredinese, but which are borne 

 in fruit bodies with open hymenia ; (3) Pileacrese, having horizontal 

 septate basidia in closed receptacles ; and (4) Tremelline?e, having verti- 

 cally 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, bear- 



