The Pezizæ are excellent Ascomycetous Fungi for exhibiting the asci, as they are more or less soft, and thus sections of them may be easily prepared, or they may readily be picked to pieces with the mounted needles.
Tuberacei.—In this family is contained the Truffle (Túber cibárium). The asci are situated upon the inner surfaces of the winding canals traversing the substance of the fleshy fruit (peridium) of which the truffle consists.
Phacidia´cei.—To this family belongs Hystérium frax´ini ([Pl. VIII.] fig. 30), which is found upon ash-twigs. The drawn-out capsules or perithecia (fig. 31) are black and elliptical, with a longitudinal fissure or orifice, and contain the asci (fig. 32) with the spores.
Sphæriácei.—Dothid´ea typhína ([Pl. VIII.] fig. 12) is a common Fungus upon the stems of living grasses. It forms an orange-coloured patch or layer encircling the stem, and covered with little dots. On making a section (fig. 14), it appears composed of a row of oblong or obovate closely placed capsules (perithecia) immersed in and continuous with a finely fibrous receptacular mass (stróma). The asci (fig. 15) are very slender, arising in a tuft from the bottom of the capsules, and containing eight still more slender spores. Except under a very high power, the spores appear as interrupted lines running down the interior of the asci. The little dots visible to the naked eye are the slightly projecting mouths of the capsules, which are more distinctly seen in the magnified portion of the Fungus (fig. 13). In the young state, this Fungus is whitish.
This Fungus cannot be mistaken for a Uredo, two species of which occur upon grasses—Uredo lineáris forming yellowish-brown spots, and Uredo rubígo yellow spots.
Dothidea ul´mi ([Pl. VIII.] fig. 24) forms black, slightly raised, and somewhat star-shaped spots upon the upper surface of the leaves of the elm. In a section (fig. 26) the cavities are seen, containing the very delicate asci (fig. 25). The spores (fig. 27) are oval, with a minute septum at one end.
Sphæ´ria rubel´la ([Pl. VIII.] fig. 16) is extremely common on the dead stems of the nettle, &c. In this Fungus the black bottle-like perithecia (fig. 18), containing the asci and paraphyses (fig. 17), are at first situated beneath the epidermis, through which they at length burst. The spores (fig. 19 a) are spindle-shaped, and from four-to seven-septate. When ripe, they escape by a hole or pore in the neck.
Sphæ´ria complanáta ([Pl. VIII.] fig. 22) is another common species, found in hedges, on dead sticks of the softer (herbaceous) plants, as the parsley-order (Umbelliferæ). Here the minute capsules, which are scattered over the stems, are at first rounded, then flattened on the top (depressed), the neck being very minute (fig. 23). The spores in this species are exceedingly minute, oblong, and not contained in asci.
Sphæ´ria bulláta also belongs to this family. It occurs upon decaying birch-sticks, presenting to the naked eye the appearance represented in [Pl. VIII.] fig. 20. The black, raised tubercles (receptacles) in their growth burst through the bark, splitting the epidermis. They consist of a white stroma (fig. 20 a), in which the bottle-shaped capsules (perithecia) are immersed, the necks projecting slightly above the surface as little points (papillæ). The tufted spore-sacs or asci (fig. 21), with the thread-like paraphyses, are contained within the capsules; and within the asci are the densely packed, very numerous and minute curved spores.
Another species, Sphæria discifor´mis, is also common on birch-sticks. It differs from the last in the tubercles being perfectly flat; the spores are also longer, straight, and spindle-shaped (fusiform).