As with other tooth fungi, the spores are produced on spines on the underside of the cap, typically between 2 and 7 cm ( 0.8 2.8 in ) in diameter, which has characteristic concentric zones of color.
22.
Their model known as concentric zone model and first published in " The City " ( 1925 ) predicted that, once fully grown, cities would take the form of five concentric rings, with areas of social and physical deterioration concentrated near the city center and more prosperous areas located near the city's edge.
