Het Leven der Dieren. Deel 3, Hoofdstuk 5: De Amphibiën

A general natural-history overview surveys amphibians' anatomy, life cycle, and habits, emphasizing their larval gill-bearing stage and later transition to lung-bearing, amphibious adults. It outlines the group's diversity in body form and limb development, variations in locomotion, and distinctive naked skin with mucus and toxin-secreting glands that enable cutaneous respiration and water uptake. The summary also describes skin-specialized structures for egg development, mechanisms of moisture regulation, and skeletal features reflecting both fish-like and more advanced vertebrate vertebrae, linking form to an ecological dependence on aquatic environments.