As originally defined by Berkeley, this group was composed chiefly of the old typical Mucors and their allies, and was then termed Physomycetes. In the newer system of classification its original definition has been extended so as to include a number of groups somewhat dissimilar in their habits and characteristics, but "united under the conservating bond of a dimorphic reproduction," and the name has been changed to Phycomycetes. As at present recognized "the Phycomycetes are characterized by a unicellular mycelium, often parasitic on plants or animals, sometimes saprophytic, developed in the air or in water. Reproduction sexual or asexual." As thus interpreted, Phycomycetes includes the Mucoracei; the Peronosporaceæ, or "rotting moulds;" the Cystopi, or "white rusts;" the Saprolegniaceæ, or "fish moulds;" the Entomophthoraceæ, or "insect moulds," together with a few minor groups of doubtful natural affinity.
BIBLIOGRAPHY.
Saccardo, P. A. "Sylloge Sphæropsidearum et Melanconiearum," in Sylloge Fungorum. Vol. iii. Imp. 8vo. Padua, 1884.
L. A. Crie. Recherches sur les Pyrenomycetes inferieurs du group de Depazées. 8vo. Paris, 1878.
J. C. Corda. Icones Fungorum. Fol. 6 vol. Prague, 1837-'54.
Bonorden. Zur Kenntniss der Coniomyceten u. Cryptomyceten. 4to. Halle, 1860.
M. C. Cooke. The Hyphomycetous Fungi of the United States. 8vo. 1877.
P. A. Saccardo. Sylloge Fungorum. Vol. iv.—"Hyphomyceteæ." Padua, 1886.