The Grihya Sutras give the rules for the numerous ceremonies applicable to the domestic life of a man and his family from birth to the grave. For the performance of their ritual only the domestic (avasathya or vaivahika) fire was required, as contrasted with the three sacrificial fires of the Çrauta Sutras. They describe forty consecrations or sacraments (samskaras) which are performed at various important epochs in the life of the individual. The first eighteen, extending from conception to marriage, are called "bodily sacraments." The remaining twenty-two are sacrifices. Eight of these, the five daily sacrifices (mahayajna) and some other "baked offerings" (pakayajna), form part of the Grihya ceremonies, the rest belonging to the Çrauta ritual. The first of the sacraments is the pumsavana or ceremony aiming at the obtainment of a son. The most common expedient prescribed is the pounded shoot of a banyan tree placed in the wife's right nostril. After the birth-rites (jata-karma), the ceremony of giving the child its names (nama-karana) takes place, generally on the tenth day after birth. Two are given, one being the "secret name," known only to the parents, as a protection against witchcraft, the other for common use. Minute directions are given as to the quality of the name; for instance, that it should contain an even number of syllables, begin with a soft letter, and have a semi-vowel in the middle; that for a Brahman it should end in -çarman, for a Kshatriya in -varman, and a Vaiçya in -gupta. Generally in the third year takes place the ceremony of tonsure (chuda-karana), when the boy's hair was cut, one or more tufts being left on the top, so that his hair might be worn after the fashion prevailing in his family. In the sixteenth year the rite of shaving the beard was performed. Its name, go-dana, or "gift of cows," is due to the fee usually having been a couple of cattle. By far the most important ceremony of boyhood was that of apprenticeship to a teacher or initiation (upanayana), which in the case of a Brahman may take place between the eighth and sixteenth year, but a few years later in the case of the Kshatriya and the Vaiçya. On this occasion the youth receives a staff, a garment, a girdle, and a cord worn over one shoulder and under the other arm. The first is made of different wood, the others of different materials according to caste. The sacred cord is the outward token of the Arya or member of one of the three highest castes, and by investiture with it he attains his second birth, being thenceforward a "twice-born" man (dvi-ja). The spiritual significance of this initiation is the right to study the Veda, and especially to recite the most sacred of prayers, the Savitri. In this ceremony the teacher (acharya) who initiates the young Brahman is regarded as his spiritual father, and the Savitri as his mother.