The first chapter of the third or supplementary part consists of fifteen sections, which are often quite short, are mostly unconnected in matter, and appear to be of very different age. The second chapter, however, forms a long and important treatise (identical with that found in the Chhandogya) on the doctrine of transmigration. The views here expressed are so much at variance with those of Yajnavalkya that this text must have originated in another Vedic school, and have been loosely attached to this Upanishad owing to the peculiar importance of its contents. The preceding and following section, which are connected with it, and are also found in the Chhandogya, must have been added at the same time. Not only is the longest Upanishad attached to the White Yajurveda, but also one of the very shortest, consisting of only eighteen stanzas. This is the Iça, which is so called from its initial word. Though forming the last chapter of the Vajasaneyi Samhita, it belongs to a rather late period. It is about contemporaneous with the latest parts of the Brihadaranyaka, is more developed in many points than the Kathaka, but seems to be older than the Çvetaçvatara. Its leading motive is to contrast him who knows himself to be the same as the Atman with him who does not possess true knowledge. It affords an excellent survey of the fundamental doctrines of the Vedanta philosophy. A large and indefinite number of Upanishads is attributed to the Atharva-veda, but the most authoritative list recognises twenty-seven altogether. They are for the most part of very late origin, being post-Vedic, and, all but three, contemporaneous with the Puranas. One of them is actually a Muhammadan treatise entitled the Alla Upanishad! The older Upanishads which belong to the first three Vedas were, with a few exceptions like the Çvetaçvatara, the dogmatic text-books of actual Vedic schools, and received their names from those schools, being connected with and supplementary to the ritual Brahmanas. The Upanishads of the Atharva-veda, on the other hand, are with few exceptions like the Mandukya and the Jabala, no longer connected with Vedic schools, but derive their names from their subject-matter or some other circumstance. They appear for the most part to represent the views of theosophic, mystic, ascetic, or sectarian associations, who wished to have an Upanishad of their own in imitation of the old Vedic schools. They became attached to the Atharva-veda not from any internal connection, but partly because the followers of the Atharva-veda desired to become possessed of dogmatic text-books of their own, and partly because the fourth Veda was not protected from the intrusion of foreign elements by the watchfulness of religious guilds like the old Vedic schools.