Note 473 — Chapter II · THE GROWTH OF THE REPUBLICAN CONSTITUTION
Reading edition
Livy (x. 6) marvels at the fact; he thinks that it must have been accidental (“morte duorum”), since the augural college should have consisted of three or of a multiple of three. Cicero (de Rep. ii. 9, 16) says that Romulus coopted (cooptavit) one from each of the three tribes; they were therefore four; that Numa added two (ib. ii. 14, 26). This makes six, which Livy (l.c.) thinks the normal number at the time of the passing of the Ogulnian law.