He is liable for wine by itself, for grapes by themselves, for grape-seeds by themselves, and for grape-skins by themselves. R’ Elazar ben Azariah says: He is not liable until he eats two grape-seeds and their grape-skin.  Which are chartzanim and which are zagim? The chartzanim are the outer part, the zagim are the inner part; [these are] the words of R’ Yehudah. R’ Yose says: [In order] that you not err, it is like the zug-bell of an animal —- the outer part [is called] zug, and the inner part inbal.

Standard nezirus is for thirty days. [If] he shaved [his head], or [if] bandits shaved it, he forfeits thirty days.  A nazir who shaved, whether with a scissors or with a razor or by plucking a minute amount, is liable.  A nazir may rub or scratch [his head], but he may not comb it. R’ Yishmael says: He may not rub it with earth since it causes the hair to fall out.