forced to run a race with Conchobar's horses. She outran them, but gave
birth immediately to twins, and, in her pangs, cursed the men of Ulster,
with a curse that, in time of oppression, they would be overcome with
the weakness of childbirth. From this Cuchulainn was exempt, for he was
not of Ulster, but a son of Lug.[456] Various attempts have been made to
explain this "debility." It may be a myth explaining a Celtic use of the
"couvade," though no example of a simultaneous tribal couvade is known,
unless we have here an instance of Westermarck's "human pairing season
in primitive times," with its consequent simultaneous birth-period for
women and couvade for men.[457] Others, with less likelihood, explain it
as a period of tabu, with cessation from work and warfare, at a funeral
or festival.[458] In any case Macha's curse is a myth explanatory of the
origin of some existing custom, the duration of which is much
exaggerated by the narrator. To this period belong also the tale of
Cuchulainn's visit to Elysium, and others to be referred to later.
Another story describes his attack upon Morrigan because she would
neither yield up the cows which she was driving away nor tell her true
name--an instance of the well-known name tabu. Morrigan took the form of
a bird, and was then recognised by Cuchulainn, who poured scorn upon
her, while she promised to oppose him during the fight of the _Tain_ in
the forms of an eel, a wolf, and a cow, all of which he vowed to
destroy.[459] Like many others in the saga, this story is introductory
to the main episode of the _Tain_. To this we now turn.

Medb had been wife of Conchobar, but, leaving him, had married in
succession two chiefs called Ailill, the second of whom had a bull,
Findbennach, the White-horned, which she resolved to match by one in
every way its equal. Having been refused the Brown Bull of Cuailgne, she
summoned all her forces to invade Ulster. The moment was inauspicious
for Ulster, for all its men were suffering from their "debility."
Cuchulainn, therefore, went out to encounter the host, and forced Medb
to agree that a succession of her warriors should engage him in single
combat. Among these was his old friend Ferdia, and nothing is so
touching as his reluctance to fight him or so pathetic as his grief when
Ferdia falls. The reluctance is primarily due to the tie of
blood-brotherhood existing between them. Finally, the Ulstermen rose in
force and defeated Medb, but not