Order 1. =Tylostomaceæ.= Capillitium present. After the rupture of the peridium the remaining part of the fruit-body is elevated on a long _stalk_. _Tylostoma mammosum_, on heaths. Order 2. =Lycoperdaceæ.= The fruit-body has a double peridium; the external one at length breaks into fragments (_Lycoperdon_, _Bovista_), or it has a compound structure of several layers (_Geaster_) and detaches itself as a continuous envelope from the inner layer, which is membranous and opens at its apex. The interior of the fruit-body consists either solely of the fertile gleba (_Bovista_, _Geaster_), or, in addition, of a sterile tissue at the base (_Lycoperdon_). A capillitium is also present. [Illustration: FIG. 180.--_Lycoperdon gemmatum_ (½ nat. size).] _Lycoperdon_ (Puff-ball) has a sterile part at the base of the fruit-body which often forms a thick stalk. The surface of the peridium is generally covered with warts or projections. When young this Fungus is edible, but when ripe it is dry, and used for stopping the flow of blood. _L. giganteum_, which is often found growing in meadows, attains a considerable size, its diameter reaching as much as eighteen inches. _L. gemmatum_ (Fig. 180) is covered with pyramidal warts; in woods.--_Bovista_ has no sterile basal part; the external peridium is smooth, and falls away in irregular patches. _B. plumbea_, on links near the sea.--_Geaster_ (Earth-star) has an external peridium composed of several layers, which when the fruit-body opens, split into several stellate segments. These segments are very hygroscopic, and in dry weather bend backwards and so raise the inner peridium into the air. The inner peridium contains the spores and capillitia. _G. coliformis_ has several apertures in the inner peridium. The other species have only one regular aperture at the apex. _G. striatus_ has a pedicellate inner peridium, with conical, striped peristome. _G. fornicatus_ has an external peridium split into four segments. This last and several other species produce “mycorhiza” on the roots of Conifers. [Illustration: FIG. 181.--I _Hymenogaster citrinus_ (nat. size); II longitudinal section through _H. tener_ (× 5); III portion of a section of _H. calosporus_; _g_ a chamber; _h_ hymenium; _sp._ spores; _t_ trama (× 178); IV _Rhizopogon luteolus_ (nat. size); V _Scleroderma vulgare_, VI section of V; VII basidia with spores belonging to the same Fungus.] Order 3. =Sclerodermataceæ.= _Capillitium_ wanting. The peridium is simple and thick, gleba with round, closed chambers, which are filled with basidia. _Scleroderma_ has a corky peridium. The fruit-bodies commence their development under ground. _S. vulgare_ (Fig. 181 V-VII), has a hard, slaty-black gleba.