Book excerpt: Physical Postures (Asanas) Are The Most Important And Often The Only Constituent Of Modern Yoga. Many Practitioners Believe That The Postures Derive From An Ancient Original Set Of Eighty-Four Asanas. This Book, For The First Time, Traces Traditions Of Eighty-Four Postures By Examining Original Materials, Including Drawings, Descriptions In Older Indic Texts And Modern Publications Which Reflect Contemporary Traditions. It Also Takes Up A Number Of Broad Issues Related To The Topic Of Yoga Postures So As To Provide The Reader With A Larger Context.