Padapāṭha. It is their object to determine the relation of these to each other. In so doing they furnish a systematic account of Vedic euphonic combination, besides adding phonetic discussions to secure the correct recitation of the sacred texts. They are generally regarded as anterior to Pāṇini, who shows unmistakable points of contact with them. It is perhaps more correct to suppose that Pāṇini used the present Prātiçākhyas in an older form, as, whenever he touches on Vedic sandhi, he is always less complete in his statements than they are, while the Prātiçākhyas, especially that of the Atharva-veda, are dependent on the terminology of the grammarians. Four of these treatises have been preserved and published. One belongs to the Rigveda, another to the Atharva-, and two to the Yajur-veda, being attached to the Vājasaneyi and the Taittirīya Saṃhitā respectively. They are so called because intended for the use of each respective branch (çākhā) of the Vedas.
The Prātiçākhya Sūtra of the Rigveda is an extensive metrical work in three books, traditionally attributed to Çaunaka, the teacher of Āçvalāyana; it may, however, in its present form only be a production of the school of Çaunaka. This Prātiçākhya was later epitomised, with the addition of some supplementary matter, in a short treatise entitled Upalekha. The Taittirīya Prātiçākhya is particularly interesting owing to the various peculiar names of teachers occurring among the twenty which it mentions. The Vājasaneyi Prātiçākhya, in eight chapters, names Kātyāyana as its author, and mentions Çaunaka among other predecessors. The Atharva-veda Prātiçākhya, in four chapters, belonging to the school of the Çaunakas, is more grammatical than the other works of this class.
