The Khecarividya of Adinatha, a Sankrrit text dated to pre1400 ce, teaches khecari-mudra, one of the most importan exercises of hathayoga, in which the tongue is inserted above the palate in order to drink the amrta or nectar of immortality dripping from the top of the skull. It is said to best- tow immortality, the ability to remain in deep meditation for long periods & the power of flight upon its practitioners. The text has been edited for the first time & has never before been accessible to an English speaking readership. It is accompanied by an introduction & an extensively annotated teanslation. The author has drawn on twenty-seven Sanskrit manuscripts & original fieldwork amongst yogins in India to demonstrate how earlier tantric yogic techniques developed & mutated into the practices of hathayoga. The work sheds new light on the develoment of hathayoga & ex- plains its practices.(NIDICA BOOKS)