On these grounds four chronological strata may be distinguished in the White Yajurveda. To the fundamental portion, comprising chapters 1-18, the next seven must first have been added, for these two parts deal with the general sacrificial ceremonial. The development of the ritual led to the compilation of the next fourteen chapters, which are concerned with ceremonies already treated (26-29) or entirely new (30-39). The last chapter apparently dates from a period when the excessive growth of ritual practices led to a reaction. It does not supply sacrificial mantras, but aims at establishing a mean between exclusive devotion to and total neglect of the sacrificial ceremonies.
Even the original portion of the White Yajurveda must have assumed shape somewhat later than any of the recensions of the Black. For the systematic and orderly distribution of matter by which the mantras are collected in the Saṃhitā, while their dogmatic explanation is entirely relegated to a Brāhmaṇa, can hardly be as old as the confused arrangement in which both parts are largely mixed up.
The two most important portions of the Yajurvedas deal with the new and full moon sacrifices, as well as the soma sacrifice, on the one hand, and with the construction of the fire-altar on the other. Chapters 1-10 of the White Yajurveda contain the mantras for the former, chapters 11-18 those for the latter part of the ceremonial. The corresponding ritual explanations are to be found in books 1-5 and 6-9 respectively of the Çatapatha Brāhmaṇa. In these fundamental portions even the Black Yajurveda does not intermingle the mantras with their explanations. The first book of the Taittirīya Saṃhitā contains in its first four lessons
