Shrinking Fairies: Narratives of how fairies became small

I’ve written about the history of tiny fairies - how fairies, always portrayed in a range of sizes, have become more likely to be depicted as only a few inches tall. This time, I’d like to look at something along the same lines: narratives explaining how fairies have dwindled over time. I’m not talking about the trope of fairies who change size at will, but the idea that fairies were once big, and are now small, because they shrank. 
 
A major theme in accounts of fairies is that they were once greater than they are now. Fairies have faded or are no longer seen. No matter how far back you go, they’re a thing of the past, always just out of reach. The Canterbury Tales, written 1387-1400, place the deeds of fairies back in “tholde dayes of the king Arthour,” and explain that “now can no man see none elves mo.” In a bit of wordplay, friars have replaced fairies as Christianity crowds out spirit-worship.
 
It’s a short step from this to the idea that the fairies haven’t simply left - they’ve shrunken. 
Standish O’Grady wrote "undoubtedly, the fairies of mediæval times are the same potent deities [as the Tuatha De Danan], but shorn of their power and reduced in stature.” Yeats also referenced this theory - the gigantic Irish gods “when no longer worshipped and fed with offerings, dwindled away in the popular imagination, and now are only a few spans high." 
These are later writings, based on the theory that the fairies are direct adaptations of pagan gods. It’s also confusing how we’re meant to take these accounts of shrinking: Are they literal? Metaphorical? Both? 
 
Stewart Sanderson responded to this kind of theory - “Personally I cannot take too seriously the confusion of moral or spiritual stature with physical stature.” So, he doubts the claim that people stopped believing in the gods as powerful, so they started envisioning them as pocket-sized. I would agree that’s kind of a stretch.
 
And what about statements like "In Cornwall, the Tommyknockers were thought to be the spirits of Jewish miners from long ago, reduced in stature until they became elf-like" (James 1992). It might indicate a narrative about gradually shrinking Jewish miners, but upon reading further, I haven’t found any explicit mention. Ghosts are simply smaller than their living counterparts in that tradition.
 
However, there are a few stories where the dwindling of the fairies from large to small is clearly literal. Most of these stories are connected to Cornwall.
 
Cornish belief tells that ants, or Muryans, are fairies “in their state of decay from off the earth,” and it is unlucky to kill an ant. (Hunt 1903)
 
In "The Fairy Dwelling on Selena Moor," the fairies are ghosts who waste away over the centuries until they cease to exist. They are also shapechangers, and “those who take animal forms get smaller and smaller with every change, till they are finally lost in the earth as muryans (ants).” (Bottrell 1873)
Here, shrinking is a natural part of the fairy life cycle, explaining why these wraiths are so much smaller than their living counterparts. The most recently deceased among their group is closer to average human stature.
 
Evans-Wentz’s collected Cornish pixy-lore mentioned that “Pixies were often supposed to be the souls of the prehistoric dwellers of this country. As such, pixies were supposed to be getting smaller and smaller until, finally, they are to vanish entirely.” 
 
The trope appeared in the more ornate, literary tale of "Wisht Wood,” by Charles Lee. Here, the Piskies, or Pobel Vean, shrink or grow in direct relation to how many people believe in them. They were once giants and gods, but when Christian missionaries sprinkled them with holy water, they shrank to the size of dwarves. They continued to progressively shrink as the last traces of pagan faith waned, until they were only a few inches tall. They feared the approaching day when “the muryons send out hunting parties to chase us from wood and more, and the quilkens [frogs] run at us open-mouthed.” (Note the mention of muryons - the piskies are not becoming ants, but they are still mentioned in connection with them.) The piskies beg a priest to tell their stories and encourage just a little belief in them, "that we may not shrink to dust". The narration closes with the idea that the pixies have clung to life, but still continue to dwindle away with modern agnosticism replacing religious censorship. This is very different from the previous examples, where shrinking is a natural part of fairy life. This is an outside condition; their size depends on human belief. I have a feeling that this story is mostly Lee’s creation, but it still has markers of Cornish folklore.
 
So far, I’ve found one other example outside Cornwall. Johann Wolfgang von Goethe's 1807 story "Die Neue Melusine" (The New Melusine) is a literary example from Germany. The “Melusine” of the title is from an ancient race of dwarfs, who are progressively shrinking - the reason given is that "everything that has once been great, must become small and decrease.” They intermarry with humans so that they won’t shrink to microscopic size. (Note that ants appear here too, as a dangerous rival nation which may attack the dwarfs.)
 
Conclusion
This is merely a beginning to researching this trope and there’s much more work to be done. However, so far there are two trends. 
First is a later, scholarly theory that the pagan gods shrank into fairies, which is partly metaphorical, and doesn’t necessarily represent folk belief. 
Second is a Cornish theme that shrinking is part of a fairy’s (or pixy’s, or muryan’s) natural life cycle. These fairies are actually ghosts, ranging from the recently dead to ancient forgotten tribes.
Goethe’s “The New Melusine” is interesting, and I wonder if there may be other German sources to be found.
If you know of any other examples of shrinking fairies, then leave them in the comments!
 
Sources

• Bottrell, William. Traditions and Hearthside Stories of West Cornwall, Vol. 2. 1873.
• Evans-Wentz, W. Y. The Fairy-Faith in Celtic Countries. 1911.
• Goethe. Wilhelm Meister's Travels. 1902. p. 328ff.
• Hunt, Robert. Popular Romances of the West of England. 1903
• James, Ronald M. “Knockers, Knackers, and Ghosts: Immigrant Folklore in the Western Mines.” Western Folklore, vol. 51, no. 2, 1992, pp. 153–177. JSTOR, www.jstor.org/stable/1499362. Accessed 21 Jan. 2021.
• Lee, Charles. "The Wisht Wood." The Cornish Magazine, Volume 1. 1898. p. 252ff.
• O'Grady, Standish. History of Ireland, Critical and Philosophical, Volume 1. 1881. p. 99
• Sanderson, Stewart. “A Prospect of Fairyland.” Folklore, vol. 75, no. 1, 1964, pp. 1–18. JSTOR, www.jstor.org/stable/1258872. Accessed 21 Jan. 2021.