Kidneys were in his mind
The opening sentences of Calypso describe a man who is considerably more at home in his body than is Stephen Dedalus, and considerably less brilliant with language. The first sentence contains an apparently unintended pun, "ate with relish," and then, as if to confirm that something is not quite right, the second paragraph begins with a supremely awkward literalism: "Kidneys were in his mind." These locutions can be read as instances of free indirect style, pulling the prose into the mental orbit of Bloom, much as the narration on the first page of the novel swung into the orbits first of Mulligan and then of Stephen.
§ The clownish ineptitude of these stylistic features notwithstanding, the chapter's opening moves the novel quite decisively, and skillfully, from Stephen's rarified intellectual meanderings to Bloom's intestinal hankerings. The effect of hearing Bloom's list of organ meats is similar to the transition that Joyce makes at the beginning of part 3 in A Portrait of the Artist as a Young Man: "The swift December dusk had come clownishly after its dull day and, as he stared through the dull square of the window of the schoolroom, he felt his belly crave for its food. He hoped there would be stew for dinner, turnips and carrots and bruised potatoes and fat mutton pieces to be ladeled out in thick peppered flourfattened sauce. Stuff it into you, his belly counseled him."
These sentences derive much of their impact from their contrast with the ending of part 2. As Stephen kisses a prostitute for the first time, bodies dissolve into abstractions: "With a sudden movement she bowed his head and joined her lips to his and he read the meaning of her movements in her frank uplifted eyes. It was too much for him. He closed his eyes, surrendering himself to her, body and mind, conscious of nothing in the world but the dark pressure of her softly parting lips. They pressed upon his brain as upon his lips as though they were the vehicle of a vague speech; and between them he felt an unknown and timid pressure, darker than the swoon of sin, softer than sound or odour." Amorous lips press upon the brain with an unknown language, and a wet tongue becomes transmogrified into something even more vague than "the swoon of sin."
Bloom's narrative takes over from Stephen's in Ulysses with a catalogue of bodily organs—"thick giblet soup, nutty gizzards, a stuffed roast heart, liverslices fried with crustcrumbs, fried hencods' roes," "grilled mutton kidneys"—not as a humiliating reminder of the spirit's enslavement to carnal sin (Stephen's condition in A Portrait), but as a lusty hymn to carnal appetite. Joyce's schemas do not assign an organ to any of the first three chapters, because Stephen barely resides in his body. Calypso is associated with an organ: the "kidney."