Reality hunger—underwater edition

From (where else?) Grognardia:

There are a lot of reasons why [Richard S. Shaver's] "I Remember Lemuria" generated such a positive response with readers, but perhaps the most likely is that it doesn't present itself as fiction at all, a pose that is aided by its copious accompanying footnotes, most of which were supplied by Amazing's editor, Ray Palmer. For example, here's a long footnote on the deros:
Pressed for a more complete explanation, Mr. Shaver has defined "dero' for us:

"Long ago it happened that certain (underground) cities were abandoned and into those cities stole many mild mortals to live, At first they were normal people, though on a lower intelligence plane; and ignorant due to lack of proper education. It was inevitable that certain inhabitants of the culture forests lose themselves and escape proper development; and some of them are of faulty development. But due to their improper handling of the life-force and ray apparatus in the abandoned cities, these apparatii became harmful in effect. They simply did not realize that the ray filters of the ray mechanisms must be changed and much of the conductive metal renewed regularly. If such renewals are not made, the apparatus collects in itself—in its metal—a disintegrant particle which gradually turns its beneficial qualities into strangely harmful ones.[...]"