Background and summaries:
Published by the American Book Company under the direction of the Department of Education at Columbia University, Jewels from the Moon and the Meteor that Couldn't Stay was created as a fifth grade school reader. The stories are designed to not require the reader to have read any of the Mushroom Planet books, while also not contradicting or repeating anything from the proper novels.
The first story, “Jewels from the Moon,” finds David and Chuck meeting an odd woman, Ms. Bronwyn, who lives in a house on the beach. They eat her delectable mushroom soup and then she takes them on a dreamlike journey through the solar system. When they try to visit her again another day, her house is just a ruin, though Mr. Bass reveals she is a Mycetian like him.
“The Meteor that Couldn't Stay” details David and Prewytt Brumblydge's journey to Arizona to investigate what they hope is a Brumblium meteor, but their discovery is thwarted by the presence of a chunk of anti-matter. Given Brumblydge's inclusion and his fate at the end of A Mystery for Mr. Bass, it's very likely that this story was an excised episode from the overlong first draft of Mr. Bass's Planetoid.
Each story features a series of questions / activities, including work with word definitions, sequencing, expressions, and descriptive language.