Vyakarana, or Grammar, was a product of this age, and the deservedly great fame of Panini, perhaps the foremost grammarian of the world, has eclipsed all other grammarians of the period. We will not enter here into the controversy of the date of this great scholar, who is thought by some to have lived in the fourth century B.C., but in our own opinion it seems not improbable that his date is to be placed before the rise of Buddhism. Whatever may be the fact, it is acknowledged that his grammatical rules affected the entire classical language of the Sanskrit and exercised an influence even on the modern science of language, which owes its existence to the opening of Sanskrit to Europe within little more than a century. Second only to Panini in ancient philological work is Yaska in the kindred department of etymology (Nirukta).
The object of Jyotisha, or Astronomy, which should likewise be mentioned here, was to give a knowledge of the heavenly bodies necessary for fixing the time for sacrifices, and to establish a sacred calendar.
Besides the six Vedangas detailed above, there is another class of works called the Anukramani, or Index to the Vedas, which also belongs to Sutra literature. The Anukramani of the Rig-Veda is ascribed to Katyayana and gives the first words of each hymn, the number of verses, the name of the poet, the metre, and the deity; and although there were older Anukramanis of the Rig-Veda, all have been superseded by Katyayana's fuller work.
The Yajur-Veda has three Anukramanis, one for