In "The Pomegranate Seeds," the story starts out with Mother Ceres (Demeter) working on ripening crops. The other version has that after Zeus (Jupiter) defeated the Titans, new enemies rose up, this time, the giants (some of which had a hundred arms, others breathed fire). They too were finally defeated, and were buried under Mt. Aetna, where they struggle to get loose, causing earthquakes, and their breath comes up, causing eruptions.
Because of the shaking, Pluto feared his kingdom might be opened to the daylight, so he came out to inspect the damage.
While he was out, Venus (Aphrodite) and Cupid saw him. Venus told Cupd, who could conquer even Zeus with his arrows, to hit Pluto with one, and make him fall in love with Persephone. Cupid got his arow, shot, and hit Pluto in the heart. Pluto saw Persephone gathering flowers with companions, fell in love, and carried her off.
In "The Pomegranate Seeds," Persephone was with sea nymphs and went up to the fields to get flowers to make wreaths for them. Pluto tempted her farther into the fields with beautiful flowers, and when she pulled up a bush of them, the hole got biggre and he grabbed her and started riding off, farther than the sun could shine.
In the other version, Pluto carries her in the chariot to the River Cyane, where he struck the bank with his trident and it gave him a passage to the Underworld.
Ceres went looking over the world for her daughter, and met a man, Celeus, who invited her to his home. When they got there, she learned that their young son was sick, and she kissed him. Instantly, he was healed. While they ate supper, Ceres put poppy juice in the boy's milk. When night came, she went to the boy's room and laid him in the ashes of the fireplace. The mother, Metanira, saw this and took him from the ashes. Ceres dropped her disguise and told the woman she was going to make him immortal. Then she said he wouldn't be immortal, but would be great among men. Then she left.
In "The Pomegranate Seeds," Ceres went searching for Persephone, and met Hecate. The two of them went to Apollo, and found what happened to Persephone. Later she met Celeus (in this version a king) and said she would help their child if they would trust him entirely to her. Then, basically, the same thing happens, except that he was not known to have eaten any food.
In the other version, after she left Celeus and Metanira, she went from land to land, and finally stood at the River Cyane. The river nymph would have told what she saw, but was afraid of Pluto. Persephone had dropped a girdle, and the nymph wafted that up through the water to Ceres. Ceres knew what had happened then, but not the cause, and blamed the land.
The nymph (Arethusa) saw this and said that the ground unwillingly opened for Pluto with Persephone. The nymph explained that she used to be a woodland nymph, and one day went into a stream. She heard a voice from under the water (Alpheus, the god of that stream). She ran away from him, and turned into a fountain after asking Diana (Artemis) for help. Diana then opened the ground, and Arethusa went down and came up in Sicily. While underground, she saw Persephone with Pluto.
Ceres then went to Zeus and asked for her daughter to be brought back. Mercury was sent with Spring to demand her release. Pluto agreed, so he let her go, but she had eaten some (doesn't say how many) pomegranate seeds, and had to spend half the time with Pluto, the rest with her mother.
Ceres agreed, and restored the earth. She remembered Celeus' son, Triptolemus, and taught him to plow and sow seeds, and took him around the world in her chariot.
In "The Pomegranate Seeds," after she left Celeus and Metanira, she cursed the Earth so nothing would grow until her daughter was returned.
Finally Quicksilver (Mercury) was sent to Pluto to ask for the release of Persephone. At the same time Quicksilver got to the front of the palace, one of Pluto's servants was bringing up for Persephone a pomegranate through the back.
While Quicksilver was speaking with Pluto, Quicksilver saw Persephone smell and take a bite of the pomegranate. Pluto didn't notice, and he let Persephone go.
Meanwhile, at her home, Ceres saw her enchanted torch flickered out, and the earth began to grow. Then Persephone came to her. She asked her daughter if she ate anything there, and Persephone said that today she had bitten into a pomegranate, and 6 seeds remained in her mouth. Ceres said that she would have to spend 1 month of every year for each seed. Persephone said it wasn't that bad, at least it wasn't the whole year.
(In still another version, Celeus' son died, and Persephone ate only 4 seeds and spent only 4 months with Pluto.)
You can see the differences in the versions such as why Hades (Pluto) kidnapped Persephone, how he did it, and how Ceres went about her search. This is because word-of-mouth stories can get changed because people exaggerate or forget a part and make up something to fill in. What one person writes down one day and what another writes down later after having heard it from others may both survive in writing, thus, you have two versions.