Taoism southern China and Taiwan may often be identified by their roofs, which feature dragons and phoenixes made from multi-colored ceramic tiles. They also stand for the harmony of yin and yang (with the phoenix representing yin). A related symbol is the flaming pearl, which may be seen on such roofs between two dragons, as well as on the hairpin of a Celestial Master. In general though, Chinese Taoist architecture lacks universal features that distinguish it from other structures. At ancient times, before Daoism Religion was founded, food may be set out as a sacrifice to the spirits of the deceased
Taijitu and called the "River Chart spontaneously generated by Heaven and Earth". By the end of the Ming period, this diagram had become a widespread representation of Chinese cosmology. The dots were introduced in the later Ming period (replacing the droplet-shapes used earlier, in the 16th century) and are encountered more frequently in the Qing period. The dots represent the seed of yin within yang and the seed of yang within yin; the idea that neither can exist without the other. Lai Zhide's design is similar to the "gakyil" ("dga' 'khyil" or "wheel of joy") symbols of Tibetan Buddhism; but while