Like many of the parasitic fungi, so destructive in the farm and the garden, this species belongs to the family in which the spores are the distinctive feature. After many botanical changes, the “smut” is at length regarded as a fixed resident in the genus _Ustilago_; with the specific name of _segetum_, which latter signifies “standing corn;” it is therefore the _Ustilago_, or _smut of the standing corn_. The characters of the genus are, chiefly, that the spores are simple and deeply seated, springing from delicate threads, or in closely-packed cells, ultimately breaking up into a powdery mass. Fifteen members of this genus have been described as British. One of these (_U. maydis_) attacks the maize or Indian corn grown in this country in a similar manner as the common smut attacks wheat or barley; but as maize is not an established crop with us, a more minute description of this species is unnecessary; the spores are figured in Plate V. fig. 108. Another species (_U. hypodytes_) makes its appearance at first beneath the sheaths of the leaves surrounding the stems of grasses (fig. 100), and ultimately appears above and around them as a purplish-black dust (fig. 101). The seeds of sedges, the leaves and stems of certain definite species of grass, the flowers of scabious (Plate VI. figs. 123-125), the receptacles of the goatsbeard, the anthers of the bladder campion, and other allied plants, and the seeds of the Bistort family, are all liable, more or less, to the attacks of one or other of the residue of the fifteen species of _Ustilago_ already referred to as indigenous to Britain. [Illustration: Plate V. W. West imp. ]