required during the search for the sacred cactus, i. 124;
at rain-making ceremonies, i. 257, 259;
required of parents of twins, i. 266;
practised before fertility ceremonies, ii. 98;
practised in order to make the crops grow, ii. 104 sqq.;
enjoined on people during the rounds of sacred pontiff, iii. 5;
of priests, iii. 6, 159 n.;
on eve of period of taboo, iii. 11;
observed by those who have handled the dead, iii. 141, 142;
during war, iii. 157, 158 n. 1, 161, 163, 164, 165;