The Grihya Sutras, Part 1 (SBE29), by Hermann Oldenberg, , at sacred-texts.com
1. In the eighth year let him initiate a Brâhmana,
2. Or in the eighth year after the conception;
3. In the eleventh a Kshatriya;
4. In the twelfth a Vaisya.
5. Until the sixteenth (year) the time has not passed for a Brâhmana;
6. Until the twenty-second for a Kshatriya;
7. Until the twenty-fourth for a Vaisya.
8. After that (time has passed), they become patitasâvitrîka (i.e. they have lost their right of learning the Sâvitrî).
9. No one should initiate such men, nor teach them, nor perform sacrifices for them, nor have intercourse with them.
10 10. (Let him initiate) the youth who is adorned and whose (hair on the) head is arranged, who wears a (new) garment that has not yet been washed, or an antelope-skin, if he is a Brâhmana, the skin of a spotted deer, if a Kshatriya, a goat's skin, if a Vaisya.
11. If they put on garments, they should put on dyed (garments): the Brâhmana a reddish yellow one, the Kshatriya a light red one, the Vaisya a yellow one.
12. Their girdles are: that of a Brâhmana made of Muñga grass, that of a Kshatriya a bow-string, that of a Vaisya woollen.
13. Their staffs are: that of a Brâhmana of Palâsa wood, that of a Kshatriya of Udumbara wood, that of a Vaisya of Bilva wood.
187:10 19, 10. By the 'arranging of the hair' the cutting of the hair is implied, as is seen from chap. 22, 22.