A study of bows between the Jomon to Yayoi period : Analysis and discussion in grate part of full-length bows

これまで、先史時代の弓矢研究は鏃の分析が中心であり、弥生時代に弓は狩猟弓から戦闘弓へと機能分化し、それに伴い弓と鏃は大型化したとの主張がなされてきた。一方、古代の研究においては、短下長上で長大な和弓がどの段階で成立するのかという議論が起こっている。近年になり、低湿地遺跡の発掘調査が増加したことで弓本体の出土事例も増え、複数の研究者により先史時代の弓について集成研究が発表された。これらの集成研究は、古代の和弓成立を考える上でも非常に重要なものである。しかし、これまでになされた集成では全長がわかる資料はほとんどなく、弓の長大化について未だ議論は深まっていない。また、集成された資料の中には弓かどうか判別し難い資料も多く、分析結果自体にも懸念材料があった。本稿では、弓の全長が確認できる完形出土品の弓を対象として集成し、全長を中心に諸要素を分析することで、縄文・弥生時代において弓がどのような変遷をたどったのか明らかにした。弓は全長によって長弓（180㎝～120㎝）・短弓（120㎝～50㎝）・小型弓（50㎝以下）に分類することができた。小型弓は縄文時代にのみみられるものの、縄文～弥生時代にかけて弓の長大化はみられず、鏃の大型化に弓の長大化が伴わないことが判明した。ただし弓の最大湾曲部の位置は、弥生時代に弓の中央部から離れる場合が多くなり、短下長上の傾向が強まっていったことは確認することができており、これは古代における和弓成立に繋がると考えられる。Until today, prehistoric bows had been studying mainly by arrowheads. In the Yayoi period, bows had been functionally differentiated from hunting bows to fighting bows, and it has been claimed that bows had become length and arrowheads had become larger. On the other hand, in the study of ancient times, there is a debate about at what stage Japanese traditional bows that are longer and have grips that are below center, were established. In recent years, the number of excavations of low-wetland sites has increased, and several researchers have published assembly studies of prehistoric bows. These assembly studies are also very important in considering the establishment of ancient Japanese bows. However, there is little material to understand to full-length in these studies, and the discussion about the length of bows has not deepened yet. In addition, there are many materials that are difficult to determine whether bow in these studies.In this article, I assembled full-length bows that can confirm total length, and analyzed various elements around total length, and clarified the changes of the bows in the Jomon and Yayoi periods. Prehistoric bows can be sorted into long bow (180cm to 120cm), short bow (120cm to 50 cm), and small bow (50 cm or less) depending on total length. Although small bows were found only in the Jomon period, it wasn’t found that bows become longer during the Jomon and Yayoi periods. In short, it seems that the increase in size of arrowheads was not related to the increase in length of bows. However, the position of the maximum curved portion of the bow is often away from the central part of the bow in the Yayoi period, it can be confirmed that the tendency to have grips that are below center has intensified, which is considered to lead to the formation of the Japanese traditional bow in ancient times