The Çrauta rites, fourteen in number, are divided into the two main groups of seven oblation (havis) sacrifices and seven soma sacrifices. Different forms of the animal sacrifice are classed with each group. The havis sacrifices consist of offerings of milk, ghee, porridge, grain, cakes, and so forth. The commonest is the Agnihotra, the daily morning and evening oblation of milk to the three fires. The most important of the others are the new and full moon sacrifices (darçapurna-masa) and those offered at the beginning of the three seasons (chaturmasya). Besides some other recurrent sacrifices, there are very many which are to be offered on some particular occasion, or for the attainment of some special object.
The various kinds of Soma sacrifices were much more complicated. Even the simplest and fundamental form, the Agnishtoma ("praise of Agni") required the ministrations of sixteen priests. This rite occupied only one day, with three pressings of soma, at morning, noon, and evening; but this day was preceded by very detailed preparatory ceremonies, one of which was the initiation (diksha) of the sacrificer and his wife. Other soma sacrifices lasted for several days up to twelve; while another class, called sattras or "sessions," extended to a year or more.
A very sacred ceremony that can be connected with the soma sacrifice is the Agnichayana, or "Piling of the fire-altar," which lasts for a year. It begins with a sacrifice of five animals. Then a long time is occupied in preparing the earthenware vessel, called ukha, in which fire is to be maintained for a year. Very elaborate rules are given both as to the ingredients, such as the hair of a black antelope, with which the clay is to be mixed, and as to how it is to be shaped, and finally burnt. Then the bricks, which have different and particular sizes, have to be built up in prescribed order. The lowest of the five strata must have 1950, all of them together, a total of 10,800 bricks. Many of these have their special name and significance. Thus the altar is gradually built up, as its bricks are placed in position, to the accompaniment of appropriate rites and verses, by a formidable array of priests. These are but some of the main points in the ceremony; but they will probably give some faint idea of the enormous complexity and the vast mass of detail, where the smallest of minutiæ are of importance, in the Brahman ritual. No other religion has ever known its like.