The parts of a mushroom consist chiefly of stem and cap; the stem has a clothy ring round its middle, and the cap is furnished underneath with numerous radiating coloured gills.
The arrangement of the conducting tissue in the stem is characteristic; a transverse section of the very young stem shows a nunber of distinct conducting strands - vascular bundles - arranged in a ring round the pith; these soon become united to form a closed ring of bast and wood, separated by a layer of formative tissue (cambium).
A second species, or race, Theropithecus obscures, distinguished by its darker hairs and the presence of a bare flesh-coloured ring round each eye, inhabits the eastern confines of Abyssinia.
The oldest rocks, consisting of slate, mica-schists and grits, which have been correlated with the metamorphic series of the eastern Highlands, form an incomplete ring round the granite in the north of the island and occupy the whole of the west coast from Loch Ranza south to Dougrie.
Its plumage is plain in colour, being of an almost uniform greyish black above, the space round the eyes and a ring round the neck being variegated with white, and a patch of pale rufous appearing above the carpal joint, while the lower parts of the body are white.
