The SPORANGIA arise either from the ordinary cells of the mycelium (_Protomyces_), or are borne on special hyphæ. They are generally spherical (_Mucor_, Fig. 80; Saprolegniaceæ), egg-, pear-, or club-shaped (Ascomycetes), more rarely they are cylindrical or spindle-shaped. While among the Phycomycetes the size, form, and number of spores are indefinite in each species, in the Ascomycetes the sporangia (_asci_) have a definite size, form, and number of spores. The spores of the Ascomycetes are known as ascospores. The sporangio-fructification is found under three main forms. 1. FREE SPORANGIOPHORES which are either single (_Mucor_, Fig. 78), or branched (_Thamnidium_). 2. SPORANGIAL-LAYERS. These are produced by a number of sessile or shortly-stalked sporangia, being formed close together like a palisade (_Taphrina_, Fig. 105). 3. SPORANGIOCARPS. These consist usually of many sporangia enclosed in a covering, they are found only in the Carpoasci, and are also known as _ascocarps_. The parts of an ascocarp are the _covering_ (_peridium_), and the _hymenium_, which is in contact with the inner wall of the peridium, and is generally made up of asci, and sterile, slender hyphæ. The latter either penetrate between the asci and are branched and multicellular (_paraphyses_, Figs. 103 _d_, 123, 125, 129), or clothe those parts of the inner wall which bear no asci (_periphyses_; among many peronocarpic Ascomycetes, _e.g. Chætomium_, _Sordaria_, _Stictosphæra hoffmanni_). The ascocarps are produced directly from the mycelium, or from a _stroma_, that is a vegetative body of various forms, in which they may be embedded (Figs. 116 _B_, _C_). Among the conidio-fructifications there are, in the same way, three divisions. 1. FREE CONIDIOPHORES (Fig. 109). The form of the conidiophores, the shape, and number of its spores are various. In the most highly developed Fungi, the Basidiomycetes, there are, however, special more highly developed conidiophores, the _basidia_, which have a definite form and spores of a definite shape and number. The conidia borne on basidia are called _basidiospores_.