Characters of Bi-peaked Tubercles on Rice Lemmas Printings from Broken Pottey Pieces Unearthed from 4 Excavation Sites in Liyang Flatlands, Hunan Studies on Chemical Composition and Structure of Lemma in Rice Stem Apex Culture and Quality Improvement of Tubercles of Pinellia ternata Ancient Rice Unearthed from Wells of the Eastern Zhou Dynasty Ruins at Daping Shuangyan of Li County in Hunan Province The Study of Ancient Cultivated Rice in China The Study on the Bi-Peak-Tubercle on Lemma of Hemudu and Luojiajiao Ancient Excavated Rice Grains with Electric Scanning Microscope