This is the first book I remember reading on my own, which would have been about 1954-55. The book was much older than that. From my hazy recollection of its appearance, I’d guess late 1920s through early 1940s. I have no memory of the title or the author. It was written at what was then probably considered a third- or fourth-grade level. There were some facing-page illustrations, but I don’t remember them clearly. It’s a story about a “cave boy” who becomes separated from his family, survives on his own, grows to young manhood, and is reunited with his family at the end. Besides that, I can remember only one specific incident: lightning strikes a tree, causing a fire, which is the occasion for the boy to discover the use of fire.

Would be delighted to find it again.