ernal evidence, such as the age of the language, and a few
allusions to events, the date of which we can approximately fix.

The language of the Triads may be described as late Old-Irish. Their
verbal system indeed is on the whole that of the Continental glosses,[9]
and would forbid us to put them later than the year 900. On the other
hand, the following peculiarities in declension, in which all the
manuscripts agree, make it impossible for us to put them much earlier
than the second half of the ninth century.

[9] I may mention particularly the relative forms _teite_ 167, _bite_
127, _ata_ 75, 76, 224, &c., _berta_ (O. Ir. _berte_) 109, 110, _fichte_
(145), _coillte_ (166), _teite_ (167), _aragellat_ (sic leg. with N)
171; the deponent _neimthigedar_ 116, &c.; _ato_, 'I am' (104), and the
use of the perfective _ad-_ in _conaittig_ 77, 78.

The genitive singular of _i-_ and _u-_stems no longer shows the ending
_-o_, which has been replaced throughout by _-a_.[10] Now, in the Annals
of Ulster, which are a sure guide in these matters and allow us to
follow the development of the language from century to century, this
genitive in _-o_ is found for the last time in A.D. 816 (_ratho,
Ailello_). Thence onward the ending _-a_ is always found.

[10] _ratha_ 56, _foglada_ 92, _flatha_ 151, 248, 253; _dara_ 4, 34;
_Ela_ 31, 35, 44 (cf. _Lainne Ela_, AU. 816); _atha_ 50, _betha_ 82, 83,
249.

The place-name _Lusca_, 'Lusk,' is originally an _n-_stem making its
genitive _Luscan_. This is the regular form in the Annals of Ulster till
the year 880, from which date onward it is always _Lusca_ (A.D. 916,
928, &c.). In our text (Sec. 46) all the manuscripts read _Lusca_.

In slender _io-_stems the dative singular in Old-Irish ends in _-iu_. I
find this form in the Annals of Ulster for the last time in A.D. 816
(_Gertidiu_). Thence onward it is always _-i_, as in our text (_hi
Cuailgni_ 43, _d'uisci_ 64).

The nasal stem _leimm_ makes its nom. plur. _leimmen_ in Old-Irish. In Sec.
32 we find instead (_tair-_)_leme_. So also _foimrimm_ makes its nom.
plural _foimrimme_ in Sec. 163.

The word _dorus_ is neuter in Old-Irish, making its nom. acc. plural
either _dorus_ or _doirsea_. In our text (Secs. 173, 174) the word is
masculine, and makes its nom. plural _doruis_.

_Druimm_ is an _i-_stem in Old-Irish, but in the later language passes
into an _n-_stem. In Sec. 51 we find the nom. pl. _drommanna_.

The neuter _grad_ in Sec. 166