The first appears to have been a peculiar druidical verse, or incantation, believed to confer upon the druid or poet the power of understanding everything that it was proper for him to say or speak.

The second is explained or translated, 'the illumination of much knowledge, as from the teacher to the pupil,' that is, that he should be able to explain and teach the four divisions of poetry or philosophy, 'and each division of them,' continues the authority quoted, 'is the chief teaching of three years of hard work.' The third qualification, or _Dichedal_, is explained, 'that he begins at once the head of his poem,' in short, to improvise extempore in correct verse.

'To the _Ollamh_,' says the ancient authority quoted in this passage in the Book of _Lecain_,' belong synchronisms, together with the _laegha laidhibh_, or illuminating poems [incantations], and to him belong the pedigrees and etymologies of names, that is, he has the pedigrees of the men of Erinn with certainty, and the branching off of their various relationships.' Lastly, 'here are the four divisions of the knowledge of poetry (or philosophy),' says the tract I have referred to; 'genealogies, synchronisms, and the reciting of (historic) tales form the first division; knowledge of the seven kinds of verse, and how to measure them by letters and syllables, form another of them; judgment of the seven kinds of poetry, another of them; lastly, _Dichedal_ [or improvisation], that is, to contemplate and recite the verses without ever thinking of them before.'"[75] The pedigrees were collected and written into a single book, called the _Cin_ or Book of Drom Snechta, by the son of Duach Galach, King of Connacht, an Ollamh in history and genealogies, &c., shortly before[76] the arrival of St.Patrick in Ireland, which happened about A.D.432.

It is obvious, therefore, that these genealogies must have existed for centuries prior to this period.

Even if they were then committed to writing for the first time, they could have been handed down for many centuries orally by the Ollamhs; for no amount of literary effort could be supposed too great for a class of men so exclusively and laboriously devoted to learning.
As the Milesians were the last of the ancient colonists, and had subdued the races previously existing in Ireland, only their genealogies, with a few exceptions, have been preserved.