The Tree of Life is a classic science fiction novelette by Catherine L. Moore (pen name C. L. Moore). This is a great story, offering a good sampling of Moore's "Weird Tales" output from the 1930's. C. L. Moore wrote alongside her husband, Harry Kuttner. The two became acquainted after Kuttner wrote her a letter, thinking (due to her pen name) that she was a man. Going by her initials was largely a practical matter; at the time Catherine Moore was writing, there was a strong prejudice that science fiction writing should be masculine, and female authors had a very difficult time getting an audience. Most notable female science fiction authors either used initials or gender-neutral pseudonyms, for a good many years after that era. It wasn't until fans dug up the obituary of James Tiptree Jr.'s mother that "he" was identified as Alice Sheldon. After all these years, "The Tree of Life" remains a great read, and excellent introduction to the works of Catherine, or C. L. Moore.