R' Meir says: We may examine negaim for the first time in order to render a lenient verdict, but not to render a stringent one.  The Sages say: [We may] not [examine a nega whether] for a lenient or for a stringent verdict.  R' Meir also said: A person may gather his father's and mother's bones [for burial], as it is a [source of] joy for him.  R' Yose says: It is [a source of] mourning for him.  A person may not inspire [lamentations] for his dead [relative], nor eulogize him during the thirty days preceding a festival.