The only other adventure of Fion's youth for which we can find space could only be suitably told in the language of the old story-tellers. See Ossianic Transactions, vol. ii. Fion thus relates the exploit:--
"I lost my way, and strayed to Lughar Diega in the south. I saw two different assemblies met on two high cairns opposite each other. One was an assembly of comely men; the other, beautiful, blooming women. There was a high, terrific precipice on either side, and a windy formidable valley between. I inquired the reason why they assumed that separate position. They informed me that Shane M'Carroll, son of Crovan, King of Kerry Luachra, was seized by a current of affection and a torrent of deep love towards Donae, daughter of Dame, and that the condition she required of him was that he should leap (over the valley) every year, but that when he came to the brink of the precipice he balked the leap. I inquired if she would marry any other man who would achieve it. She replied that she never saw a man with worse clothing than myself (this dress consisted of the skins of the animals lately slain by him for food; hence his title at the time, 'Giolla na Chroicean '--the fellow in the skins), but that she found no fault with my personal appearance, and that she would accept me if I succeeded. I thereupon tucked myself up in my skins, took my race to the margin of the precipice, and sprang over in a truly swift, scientific manner to the opposite side. I then with a high, light, airy bound, sprang back, and the princess gave me fit clothing, and becathë my wife, binding me by solemn geasach to perform the same feat every year."
Fion always succeeded--one unlucky day excepted, on the morning of which he had met a hare or a red-haired woman as he approached the chasm.
As the Druid of Boyne had predicted, Fion, after making some demonstrations in Conacht, and punishing some of the foes of his family, and obtaining the favour of the King of Munster, began to engross the attention of King Cormac. He appreciated the advantage it would be to the general weal to secure the services of a chief distinguished by heroism, and endowed with such supernatural qualities as Fion possessed. So he summoned Goll to his presence, and so wrought on him by his persuasive powers (Goll was more dogged than ambitious), that he consented to hold second rank in the national militia, In the Ossianic rhapsodies he aids his chief merely through a principle of loyalty. When immniment danger approaches, he fearlessly meets it, but is never forward to undertake any of the chivalrous enterprises so frequent in the history of the body; he finds it impossible to forget that Fion's father perished by his hand. He is more redoubtable in fight than Fion himself, being only excelled by Diarmuid and the peerless Oscur. Diarmujd bears a certain resemblance, in character and fortune, to Sir Launcelot and Sir Tristrem; Fion himself to King Arthur and Agamemnon. The bald Conan is Thersites, not altogether devoid of animal courage; Goll himself is an amalgamation of Ajax and Diomed, and the rest are amiable and noble-minded as Don Quixote himself, but destitute of any striking characteristics, except in the article of fleetness possessed by Caeilte Mac Ronan, poetic inspiration by Oisin, Fergus, &c.