These colleges have been often, but erroneously, confounded with the priesthoods.

The priesthoods were charged with the worship of a specific divinity; the skilled colleges, on the other hand, were charged with the preservation of traditional rules regarding those more general religious observances, the proper fulfilment of which implied a certain amount of knowledge and rendered it necessary that the state in its own interest should provide for the faithful transmission of that knowledge.

These close corporations supplying their own vacancies, of course from the ranks of the burgesses, became in this way the depositaries of skilled arts and sciences.
Augurs--Pontifices Under the Roman constitution and that of the Latin communities in general there were originally but two such colleges; that of the augurs and that of the Pontifices.( 11) The six "bird-carriers" (-augures-) were skilled in interpreting the language of the gods from the flight of birds; an art which was prosecuted with great earnestness and reduced to a quasi-scientific system.

The six "bridge-builders" (-Pontifices-) derived their name from their function, as sacred as it was politically important, of conducting the building and demolition of the bridge over the Tiber.

They were the Roman engineers, who understood the mystery of measures and numbers; whence there devolved upon them also the duty of managing the calendar of the state, of proclaiming to the people the time of new and full moon and the days of festivals, and of seeing that every religious and every judicial act took place on the right day.