ast aiding conception,--a belief held by other races,[1206]--this may
have given rise to myths regarding the rebirth of gods by human mothers.
At all events this latter Celtic belief is paralleled by the American
Indian myths, e.g. of the Thlinkeet god Yehl who transformed himself now
into a pebble, now into a blade of grass, and, being thus swallowed by
women, was reborn.

In the stories of Etain and of Lud, reborn as Setanta, this idea of
divine transformation and rebirth occurs. A similar idea may underlie
the tale of Fionn and Mongan. As to the tales of Gwion and the
Swineherds, the latter the servants of gods, and perhaps themselves
regarded once as divinities, who in their rebirth as bulls are certainly
divine animals, they present some features which require further
consideration. The previous transformations in both cases belong to the
Transformation Combat formula of many _Maerchen_, and obviously were not
part of the original form of the myths. In all such _Maerchen_ the
antagonists are males, hence the rebirth incident could not form part of
them. In the Welsh tale of Gwion and in the corresponding Taliesin poem,
the ingenious fusion of the _Maerchen_ formula with an existing myth of
rebirth must have taken place at an early date.[1207] This is also true
of _The Two Swineherds_, but in this case, since the myth told how two
gods took the form of worms and were reborn of cows, the formula had to
be altered. Both remain alive at the end of the combat, contrary to the
usual formula, because both were males and both were reborn. The fusion
is skilful, because the reborn personages preserve a remembrance of
their former transformations,[1208] just as Mongan knows of his former
existence as Fionn. In other cases there is no such remembrance. Etain
had forgotten her former existence, and Cuchulainn does not appear to
know that he is a rebirth of Lug.

The relation of Lug to Cuchulainn deserves further inquiry. While the
god is reborn he is also existing as Lug, just as having been swallowed
as a worm by Dechtire, he appears in his divine form and tells her he
will be born of her. In the _Tain_ he appears fighting for Cuchulainn,
whom he there calls his son. There are thus two aspects of the hero's
relationship to Lug; in one he is a rebirth of the god, in the other he
is his son, as indeed he seems to represent himself in _The Wooing of
Emer_, and as he is called by Laborcham just before his death.[1209] In
one of