By the classical period the srauta system was already archaic. Temple images, puja and the devotional currents of Hinduism offered forms of worship the solemn sacrifices could not match for accessibility, and the ethical turn against animal slaughter, pressed by Buddhism, Jainism and much of Hindu opinion itself, removed the great rites' centrepiece from respectability. The medieval and modern centuries reduced the system to scattered survivals. But the survivals are real, and their fidelity is astonishing.
Communities in Maharashtra, Andhra, Tamil Nadu and above all the Nambudiri brahmins of Kerala maintained the fires, the recitation and the ritual competence across the entire span, transmitting the texts by the mnemonic disciplines that kept Vedic sound unchanged for three thousand years. When the Nambudiris performed the agnicayana at Panjal in 1975, the scholars who documented it, led by Frits Staal, argued they were watching among the oldest continuously transmitted rituals on earth. The srauta survivals have since become a crossing point of philology, anthropology and the study of ritual as such: Staal used them to argue his famous thesis that ritual is meaningless in the sense of being pure rule-governed activity, older than the meanings assigned to it, a claim other scholars contest precisely because the tradition assigns meanings so abundantly. The atlas records the individual great rites, the agnicayana, the ashvamedha and the soma sacrifice, in their own entries; this entry holds the system they belong to.