Qumu (Cortex Ailanthi), see the entry under Chunmu (Cortex Toosendan).

Longgu (Fossil bones of ancient large mammals), along with their teeth and horns, are produced in river valleys of Jin region and in soil caves at the rocky shores of Mount Tai where dead dragons were located. Currently, they are abundant in various prefectures of Hedong Circuit. Some claim they are shed skins of dragons, but in reality, they are not true dead bones; rather, they are obtained from the dragon's spinal column and brain bone, displaying a white background with brocade-like patterns. Those that adhere to the tongue when licked are considered superior. The teeth are small and hard, retaining the shape of teeth; the horns are hard and solid. There is no fixed time for collection. Li Zhao stated in *Guoshi Bu* (Supplement to the History of the State): "When spring waters rise, fish leap over the Dragon Gate, shedding many bones. People collect them as medicine, some exhibiting five colors." *Shennong Bencao Jing* (Divine Farmer's Materia Medica) states that Longgu originates from Jin region, and since Longmen (Dragon Gate) is also in Jin, could it be that the so-called Longgu today are actually the bones of these fish? It is said that Longgu has male and female distinctions: those with fine and broad textures are female; those with coarse and narrow textures are male. For medicinal use, specimens possessing all five colors are best, followed by yellowish-white ones, while black ones are inferior. They must not come into contact with unclean places, otherwise they become unusable. Bones and teeth are commonly used by physicians, while horns are rarely used. Only Shen Shi's *Wuxie Wan* (Five Evils Pill) uses dragon horn, stating that if horns are unavailable, teeth may be substituted. *Qianjin Fang* (Essential Prescriptions Worth a Thousand Gold) for treating heart conditions includes the combined use of Longchi (Dragon Teeth) and Longjiao (Dragon Horns). Wei Dan treated wind-heat epilepsy affecting the heart by taking rotten dragon horns, grinding them thickly to extract juice, administering two large *he* (ancient unit of volume) after meals, twice daily. Thus, rotten dragon horns exist, indicating this substance is generally rare in the world. Sun Guangxian wrote in *Beimeng Suoyan* (Gossip from the Northern Dream): "During the Later Jin period, on the border between Zhenzhou and Xingtai, a dragon was fought to death. A local wealthy man named Cao Kuan saw it and took its pair of horns. In front of the horns was an object resembling blue color, with patterns like chaotic brocade, which no one recognized. Less than a year later, Cao Kuan was killed by bandits, and the military governor of Zhenzhou was soon executed." It is also said: "People from the sea say that dragons lay two eggs each time; one hatches into Jidiao (a mythical creature or specific animal). Jidiao often associates with deer. Sometimes it leaves secretions by the water, which stick to floating driftwood, forming shapes like rush-mat pestles. Their color is slightly greenish-yellow, resembling grey, known as Zishaohua (Purple Tip Flower), frequently used in sitz bath decoctions." *Yanling Zhibao Fang* (Prescription for Prolonging Life and Treasuring Treasure) for treating deafness, regardless of duration, suggests using Jidiao fat. Take an amount equivalent to half an almond grain daily, insert into the ear, and the condition will improve. It is claimed that this substance is not difficult to obtain in Fujian prefectures. Its fat must be stored in glass bottles and further sealed in camphor wood boxes; otherwise, it will lose potency due to air exposure. Additionally, *Qiefang Zhong* (Prescriptions in the Chest Box) records treatment for women whose menstruation has been absent for years, requiring intervention. Use small amounts of Longtai (Dragon Fetus), Wasong (Moss growing on roof tiles), and Jingtian (Sedum aizoon). Decoct three ingredients in two *zhan* (ancient unit of volume) of water until one *zhan* remains. Remove dregs and divide into two warm doses. After a short while, abdominal movement occurs, and Longtai is expelled. This prescription is not seen in ancient or modern formularies, and few people recognize it. The note for this formula states: "This substance comes from large streams in mountain ravines of Shu. It resembles dried fish scales. When added to decoctions, it emits a strong fishy and musky odor. Physicians rarely hear of or see it. Although not an essential drug, ancients did use it. There should be those who recognize it in the world. Therefore, it is appended here to demonstrate comprehensive recording."