I’m not a big fan of literary criticism in any field (although I have committed some), but one of my big books from my late teens onward was Le Guin’s The Language of the Night (1979), especially for the essays “From Elfland to Poughkeepsie” and “A Citizen of Mondath”.
Le Guin has some great passages in “Citizen” about what she liked to read as a kid, and how she liked it.
We kids read science fiction in the early forties: Thrilling Wonder, and Astounding in that giant format it had for a while, and so on. I liked “Lewis Padgett” best, and looked for his stories, but we looked for the trashiest magazines, mostly, because we liked trash. I recall one story that began “In the beginning was the Bird.” We really dug that bird. And the closing line from another (or the same?)—“Back to the saurian ooze from whence it sprung!” Karl made that into a useful chant: The saurian ooze from which it sprung / Unwept, unhonor’d, and unsung. I wonder how many hack writers who think they are writing down to “naive kids” and “teenagers” realize the kind of pleasure they sometimes give their readers. If they did, they would sink back into the saurian ooze from whence they sprung.
I’m pretty sure the first story she refers to is “The Unpleasant Profession of Jonathan Hoag” by Heinlein in Unknown (Oct 1942). It appeared under the false whiskers of “John Riverside” because at the time the Heinlein byline was reserved by John W. Campbell for RAH’s “future history” stories.

I never figured I’d find the source of the mysterious “saurian ooze”–except that maybe I just did. In looking for Henry Kuttner stories online I found this opus in Strange Tales (Aug, 1939). The appearance is pseudonymous, because he had a “Prince Raynor” novelette in the issue under his own name. And the crucial phrase was from the editorial blurb rather than the story itself.
Kuttner, of course, was roughly half of “Lewis Padgett”, along with C.L. Moore. And most of their work, whatever name it appeared under, seems to have been collaborative from the time they met and married, so Moore may have exuded some of that saurian ooze herself.
Le Guin’s accounts don’t exactly match up with these texts: “In the Beginning was the Bird” is a ritual phrase used by the Sons of the Bird in Heinlein’s story (one of his best fantasies, by the way), but it’s not the opener of the story. And the saurian ooze springs out at the reader at the Kuttner story’s beginning, not its end (and with a shift of ablaut at that). But given that Le Guin was writing about these stories 20-30 years after she’d read them, I’d say the shoes fit the footnotes pretty well.