The volume surveys natural luminescence across animal, plant, and mineral realms, emphasizing marine bioluminescence from surface foam to abyssal depths. It catalogs luminous protozoans, jellyfishes, fishes, crustaceans, echinoderms, shell-bearing and subterranean forms, and terrestrial examples such as fireflies, glowing fungi, and luminescent minerals, with illustrative plates and systematic chapter divisions. Field observations and simple experiments are presented alongside descriptions of appearances and possible functions of light, and reflections on human interactions with the phenomenon. An appendix and bibliography provide technical references for further study, while the tone and organization aim to engage young naturalists and general readers.