The Aranyakas and Upanishads represent a phase of language which on the whole closely approaches to classical Sanskrit, the oldest Upanishads occupying a position linguistically midway between the Brahmanas and the Sutras. Of the two Brahmanas attached to the Rigveda, the more important is the Aitareya. The extant text consists of forty chapters (adhyaya) divided into eight books called panchikas or "pentads," because containing five chapters each. That its last ten chapters were a later addition appears likely both from internal evidence and from the fact that the closely related Çankhayana Brahmana contains nothing corresponding to their subject-matter, which is dealt with in the Çankhayana Sutra. The last three books would further appear to have been composed at a later date than the first five, since the perfect in the former is used as a narrative tense, while in the latter it still has its original present force, as in the oldest Brahmanas. The essential part of this Brahmana deals with the soma sacrifice. It treats first (1-16) of the soma rite called Agnishtoma, which lasts one day, then (17-18) of that called Gavamayana, which lasts 360 days, and thirdly (19-24) of the Dvadaçaha or "twelve days' rite." The next part (25-32), which is concerned with the Agnihotra or "fire sacrifice" and other matters, has the character of a supplement. The last portion (33-40), dealing with the ceremonies of the inauguration of the king and with the position of his domestic priest, bears similar signs of lateness. The other Brahmana of the Rigveda, which goes by the name of Kaushitaki as well as Çankhayana, consists of thirty chapters. Its subject-matter is, on the whole, the same as that of the original part of the Aitareya (i.-v.), but is wider. For in its opening chapters it goes through the setting up of the sacred fire (agni-adhana), the daily morning and evening sacrifice (agnihotra), the new and full moon ritual, and the four-monthly sacrifices. The Soma sacrifice, however, occupies the chief position even here. The more definite and methodical treatment of the ritual in the Kaushitaki would seem to indicate that this Brahmana was composed at a later date than the first five books of the Aitareya. Such a conclusion is, however, not altogether borne out by a comparison of the linguistic data of these two works. Professor Weber argues from the occurrence in one passage of Içana and Mahadeva as designations of the god who was later exclusively called Çiva, that the Kaushitaki Brahmana was composed at about the same time as the latest books of the White Yajurveda and those parts of the Atharva-veda and of the Çatapatha Brahmana in which these appellations of the same god are found.