Cathal was king of Munster, and Fergal was king of Ulster, with an intense rivalry between them as both wanted to be high king. Fergal's sister, Leah, fell in love with Cathal and sent him delicacies. Fergal summoned his wizard and ordered him to perform his mystical practices so that whoever eats them will never again have a day's health for the rest of his life. When the apples entered Cathal's stomach, they turned into worms, but one large worm consumed all the others. From then on, Cathal was constantly ravenously hungry, and he ate the food belonging to everyone in his palace and in the areas he travelled through. Ronan, a medical student, eventually realized the monster could be evicted by the same way he had entered it, by fasting and appealing to the power of the church. Ronan convinced the king to fast and give him apples based on religious numbers. One was for God, 3 was for the Trinity, 4 for the books of the gospels, 5 for the books of Moses, 8 for the beatitudes, 12 for the twelve apostles, 13 for Christ with the apostles. Ronan eventually got Cathal to fast to save Ronan's soul from damnation. The demon was eventually evicted by holding food up to Cathal's mouth but refusing to let him eat it. The palace was set on fire, and the demon was destroyed within it. The demon appeared like a lizard swaying in Cathal's mouth before eviction.

Many of the Irish legends, superstitions, and ancient charms now collected were obtained chiefly from oral communications made by the peasantry themselves, either in Irish or in the Irish-English which preserves so much of the expressive idiom of the antique tongue. These narrations were taken down by competent persons skilled in both languages, and as far as possible in the very words of the narrator; so that much of the primitive simplicity of the style has been retained, while the legends have a peculiar and special value as coming direct from the national heart.

Many of the Irish legends, superstitions, and ancient charms now collected were obtained chiefly from oral communications made by the peasantry themselves, either in Irish or in the Irish-English which preserves so much of the expressive idiom of the antique tongue. These narrations were taken down by competent persons skilled in both languages, and as far as possible in the very words of the narrator; so that much of the primitive simplicity of the style has been retained, while the legends have a peculiar and special value as coming direct from the national heart.

The ancient legends of all nations of the world, on which from age to age the generations of man have been nurtured, bear so striking a resemblance to each other that we are led to believe there was once a period when the whole human family was of one creed and one language. But with increasing numbers came the necessity of dispersion; and that ceaseless migration was commenced of the tribes of the earth from the Eastern cradle of their race which has now continued for thousands of years with undiminished activity. From the beautiful Eden-land at the head of the Persian Gulf, where creeds and culture rose to life, the first migrations emanated, and were naturally directed along the line of the great rivers, by the Euphrates and the Tigris and southward by the Nile; and there the first mighty cities of the world were built, and the first mighty kingdoms of the East began to send out colonies to take possession of the unknown silent world around them. From Persia, Assyria, and Egypt, to Greece and the Isles of the Sea, went forth the wandering tribes, carrying with them, as signs of their origin, broken fragments of the primal creed, and broken idioms of the primal tongue—those early pages in the history of the human race, eternal and indestructible, which hundreds of centuries have not been able to obliterate from the mind of man. But as the early tribes diverged from the central parent stock, the creed and the language began to assume new forms, according as new habits of life and modes of thought were developed amongst the wandering people, by the influence of climate and the contemplation of new and striking natural phenomena in the lands where they found a resting-place or a home. Still, amongst all nations a basis remained of the primal creed and language, easily to be traced through all the mutations caused by circumstances in human thought, either by higher culture or by the debasement to which both language and symbols are subjected amongst rude and illiterate tribes. To reconstruct the primal creed and language of humanity from these scattered and broken fragments, is the task which is now exciting so keenly the energies of the ardent and learned ethnographers of Europe; as yet, indeed, with but small success as regards language, for not more, perhaps, than twenty words which the philologists consider may have belonged to the original tongue have been discovered; that is, certain objects or ideas are found represented in all languages by the same words, and therefore the philologist concludes that these words must have been associated with the ideas from the earliest dawn of language; and as the words express chiefly the relations of the human family to each other, they remained fixed in the minds of the wandering tribes, untouched and unchanged by all the diversities of their subsequent experience of life. Meanwhile, in Europe there is diligent study of the ancient myths, legends, and traditions of the world, in order to extract from them that information respecting the early modes of thought prevalent amongst the primitive race, and also the lines of the first migrations, which no other monuments of antiquity are so well able to give. Traditions, like rays of light, take their colour from the medium through which they pass; but the scientific mythographic student knows how to eliminate the accidental addition from the true primal basis, which remains fixed and unchangeable; and from the numerous myths and legends of the nations of the earth, which bear so striking a conformity to each other that they point to a common origin, he will be able to reconstruct the first articles of belief in the creed of humanity, and to pronounce almost with certainty upon the primal source of the lines of human life that now traverse the globe in all directions. This source of all life, creed, and culture now on earth, there is no reason to doubt, will be found in Iran, or Persia as we call it, and in the ancient legends and language of the great Iranian people, the head and noblest type of the Aryan races. Endowed with splendid physical beauty, noble intellect, and a rich musical language, the Iranians had also a lofty sense of the relation between man and the spiritual world. They admitted no idols into their temples; their God was the One Supreme Creator and Upholder of all things, whose symbol was the sun and the pure, elemental fire. But as the world grew older and more wicked the pure primal doctrines were obscured by human fancies, the symbol came to be worshipped in place of the God, and the debased idolatries of Babylon, Assyria, and the Canaanite nations were the result. Egypt—grave, wise, learned, mournful Egypt—retained most of the primal truth; but truth was held by the priests as too precious for the crowd, and so they preserved it carefully for themselves and their own caste. They alone knew the ancient and cryptic meaning of the symbols; the people were allowed only to see the outward and visible sign.